Added associate sites to update site

Eclipse Capra relies on a number of dependencies that have their own
update sites. In the past, when installing Capra from its update site,
these dependencies were not automatically picked up. This meant that not
all items the user selected were installed (e.g., the PlantUML
visualisation was not installed) if the prerequisites weren't already
present. This change adds required external update sites as "associate
sites" which allows p2 to automatically resolve the dependencies.

Change-Id: I64f5fa7984660ef385cbb48bb88f22bfcbbb0ddf
diff --git a/releng/org.eclipse.capra.releng.p2/pom.xml b/releng/org.eclipse.capra.releng.p2/pom.xml
index 5d5524e..f75e3a9 100644
--- a/releng/org.eclipse.capra.releng.p2/pom.xml
+++ b/releng/org.eclipse.capra.releng.p2/pom.xml
@@ -1,80 +1,85 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?><!--
-    Copyright (c) 2016, 2019 Chalmers | University of Gothenburg, rt-labs and others.
-    All rights reserved. This program and the accompanying materials
-    are made available under the terms of the Eclipse Public License v2.0
-    which accompanies this distribution, and is available at
-    http://www.eclipse.org/legal/epl-v20.html
-     
-    SPDX-License-Identifier: EPL-2.0
-     
-    Contributors:
-         Chalmers | University of Gothenburg and rt-labs - initial API and implementation and/or initial documentation
-         Chalmers | University of Gothenburg - additional features, updated API
- --><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <relativePath>../../pom.xml</relativePath>
-    <groupId>org.eclipse.capra</groupId>
-    <artifactId>parent</artifactId>
-    <version>0.7.1-SNAPSHOT</version>
-  </parent>
-  <groupId>org.eclipse.capra</groupId>
-  <artifactId>org.eclipse.capra.p2</artifactId>
-  <version>0.7.1-SNAPSHOT</version>
-  <packaging>eclipse-repository</packaging>
-  <name>Eclipse Capra Update Site</name>
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><!-- Copyright (c) 
+	2016, 2019 Chalmers | University of Gothenburg, rt-labs and others. All rights 
+	reserved. This program and the accompanying materials are made available 
+	under the terms of the Eclipse Public License v2.0 which accompanies this 
+	distribution, and is available at http://www.eclipse.org/legal/epl-v20.html 
+	SPDX-License-Identifier: EPL-2.0 Contributors: Chalmers | University of Gothenburg 
+	and rt-labs - initial API and implementation and/or initial documentation 
+	Chalmers | University of Gothenburg - additional features, updated API -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<relativePath>../../pom.xml</relativePath>
+		<groupId>org.eclipse.capra</groupId>
+		<artifactId>parent</artifactId>
+		<version>0.7.1-SNAPSHOT</version>
+	</parent>
+	<groupId>org.eclipse.capra</groupId>
+	<artifactId>org.eclipse.capra.p2</artifactId>
+	<version>0.7.1-SNAPSHOT</version>
+	<packaging>eclipse-repository</packaging>
+	<name>Eclipse Capra Update Site</name>
 
-  <pluginRepositories>
-    <pluginRepository>
-      <id>jboss-public-repository-group</id>
-      <name>JBoss Public Repository Group</name>
-      <url>http://repository.jboss.org/nexus/content/groups/public/</url>
-    </pluginRepository>
+	<pluginRepositories>
+		<pluginRepository>
+			<id>jboss-public-repository-group</id>
+			<name>JBoss Public Repository Group</name>
+			<url>http://repository.jboss.org/nexus/content/groups/public/</url>
+		</pluginRepository>
 
-    <pluginRepository>
-      <id>jboss-snapshots-repository</id>
-      <name>JBoss Snapshots Repository</name>
-      <url>https://repository.jboss.org/nexus/content/repositories/snapshots/</url>
-    </pluginRepository>
-  </pluginRepositories>
+		<pluginRepository>
+			<id>jboss-snapshots-repository</id>
+			<name>JBoss Snapshots Repository</name>
+			<url>https://repository.jboss.org/nexus/content/repositories/snapshots/</url>
+		</pluginRepository>
+	</pluginRepositories>
 
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.eclipse.tycho</groupId>
-        <artifactId>tycho-p2-repository-plugin</artifactId>
-        <version>${tycho-version}</version>
-      </plugin>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.eclipse.tycho</groupId>
+				<artifactId>tycho-p2-repository-plugin</artifactId>
+				<version>${tycho-version}</version>
+			</plugin>
 
-      <!-- Generate HTML version of update site -->
-      <!-- Also add additional repositories. Note that this
-           information could be entered in category.xml but Tycho
-           ignores it currently. See
-           https://bugs.eclipse.org/bugs/show_bug.cgi?id=453708 -->
-      <plugin>
-        <groupId>org.jboss.tools.tycho-plugins</groupId>
-        <artifactId>repository-utils</artifactId>
-        <version>${org.jboss.tools.tycho-plugins.version}</version>
+			<!-- Generate HTML version of update site -->
+			<!-- Also add additional repositories. Note that this information could 
+				be entered in category.xml but Tycho ignores it currently. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=453708 -->
+			<plugin>
+				<groupId>org.jboss.tools.tycho-plugins</groupId>
+				<artifactId>repository-utils</artifactId>
+				<version>${org.jboss.tools.tycho-plugins.version}</version>
 
-        <executions>
-          <execution>
-            <id>generate-facade</id>
-            <phase>package</phase>
+				<executions>
+					<execution>
+						<id>generate-facade</id>
+						<phase>package</phase>
 
-            <goals>
-              <goal>generate-repository-facade</goal>
-            </goals>
+						<goals>
+							<goal>generate-repository-facade</goal>
+						</goals>
 
-            <configuration>
-              <siteTemplateFolder>siteTemplate</siteTemplateFolder>
+						<configuration>
+							<siteTemplateFolder>siteTemplate</siteTemplateFolder>
 
-              <symbols>
-                <update.site.name>${project.parent.name}</update.site.name>
-              </symbols>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-    </plugins>
-  </build>
+							<symbols>
+								<update.site.name>${project.parent.name}</update.site.name>
+							</symbols>
+
+							<!-- this adds references to repositories of dependencies to the update site's content.xml -->
+							<associateSites>
+								<site>http://hallvard.github.io/plantuml/</site> <!-- PlantUML -->
+								<site>http://featureide.cs.ovgu.de/update/v3/</site> <!-- FeatureIDE -->
+								<site>http://download.eclipse.org/sphinx/releases/0.8.x/</site> <!-- Sphinx for ProR -->
+								<site>http://download.eclipse.org/rmf/updates/releases/0.13.0/</site> <!-- ProR for ReqIF -->
+								<site>http://download.eclipse.org/tools/gef/gef4/updates/releases/</site> <!-- GEF4 for Zest -->
+							</associateSites>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>