Collapse All Properties

This results in compilation building a single large Javascript download
instead of one for each browser/language combination. In production,
minification reduces the size of this file to something
reasonable. However if you build directly from master, this one file
will be pretty large. However it will work just fine.

This changes significantly speeds up the build process.

Change-Id: I330faf96fd95e538e3c19130c85c3ae8dbb077df

appinventor/appengine/src/com/google/appinventor/YaClient.gwt.xml

@@ -133,5 +133,6 @@
   <extend-property name="locale" values="nl"/>
 
   <set-property-fallback name="locale" value="en"/>
+  <collapse-all-properties/>
 
 </module>