Bug 365018 - [CSS] Add missing support to CSS engine

Need a build.properties, or it won't work.
diff --git a/features/org.eclipse.e4.tools.css.spy.feature/build.properties b/features/org.eclipse.e4.tools.css.spy.feature/build.properties
new file mode 100644
index 0000000..3104d6d
--- /dev/null
+++ b/features/org.eclipse.e4.tools.css.spy.feature/build.properties
@@ -0,0 +1,2 @@
+bin.includes = feature.xml,\

+               feature.properties