bug 452716: add about.html to all plug-ins

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.ui.tests/build.properties b/org.eclipse.vex.ui.tests/build.properties
index 68a74f0..da03b83 100644
--- a/org.eclipse.vex.ui.tests/build.properties
+++ b/org.eclipse.vex.ui.tests/build.properties
@@ -4,4 +4,6 @@
                .,\
                plugin.properties,\
                plugin.xml,\
-               testdata/
+               testdata/,\
+               about.html
+src.includes = about.html