Use identity semantics when canonicalizing JsonSplittable instances.
This is necessary to support Android, where the org.json arrays appear to have value-based equality.
http://code.google.com/p/google-web-toolkit/issues/detail?id=6390
Patch by: bobv
Review by: rjrjr

Review at http://gwt-code-reviews.appspot.com/1451805


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10252 8db76d5a-ed1c-0410-87a9-c151d255dfc7