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

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.docbook/build.properties b/org.eclipse.vex.docbook/build.properties
index 93ada84..dfaa7a5 100644
--- a/org.eclipse.vex.docbook/build.properties
+++ b/org.eclipse.vex.docbook/build.properties
@@ -4,9 +4,11 @@
                plugin.properties,\
                META-INF/,\
                4.5/,\
-               5.0/
+               5.0/,\
+               about.html
 src.includes = styles/,\
                4.5/,\
-               5.0/
+               5.0/,\
+               about.html
 jars.compile.order = .