[563042] Migrating to the new Xtext generator workflow.

-------------- I. org.eclipse.emf.ecore.xcore plugin ------------------
1. Modify the GenerateXcore.mwe2 workflow to use the new Xtext generator
workflow (org.eclipse.xtext.xtext.generator.*) packages instead of the
old deprecated generator workflow (org.eclipse.xtext.generator.*)
packages.
2. Rename XcoreJavaValidator to XcoreValidator.
3. Update generated code in the src-gen folder.

-------------- II. org.eclipse.emf.ecore.xcore.ui plugin --------------
1. Move the content assist infrastructure from the
org.eclipse.emf.ecore.xcore.ui package into the
org.eclipse.emf.ecore.xcore.ide package.
2. Rename XcoreEditor to CustomXcoreEditor to avoid naming collision
with the generated editor. Modify the hand-written CustomXcoreEditor to
inherit from the generated XcoreEditor.
3. Update plugin.xml_gen
4. Merge plugin.xml_gen into plugin.xml.

-------------- III. org.eclipse.emf.test.ecore.xcore plugin -----------
1. Move the XcoreInjectorProvider from the org.eclipse.emf.ecore.xcore
package to the org.eclipse.emf.ecore.xcore.tests package.
2. Add generated XcoreUiInjectorProvider class.
3. Update META-INF/MANIFEST.MF file.

-------------- IV. Versions and Builds --------------------------------

1. Modify the lower bounds of plugin dependencies because minimally
Xtext 2.18 is required
2. Ensure that all plugin dependencies have version ranges.
2. Modify the releng POMs so that the build of Xcore and the site, which
depends on Xcore, is disabled for target platforms < 2019-06.

Change-Id: I81e446995025832dc2e84decc818cfe533293ff4
Signed-off-by: Tamas Miklossy <miklossy@itemis.de>
108 files changed