Add CEF API hash and version info retrieval functions (issue #914).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1160 5089003a-bbd8-11dd-ad1f-f1f9622dbc98
Use the platform API hash instead of build revision for checking libcef compatibility (issue #914).

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk/cef3@1161 5089003a-bbd8-11dd-ad1f-f1f9622dbc98