Bug 634839 (part 2a) - Remove unnecessary headers (as found by include-what-you-use) from jsapi.h.  r=jorendorff.

--HG--
extra : rebase_source : 97759f6ed55447d66987b894b215ab1e4815b3c3
Bug 634839 (part 2b) - Remove more unnecessary headers (as found by include-what-you-use) from SpiderMonkey.  r=jorendorff.

--HG--
extra : rebase_source : 5d6a4d653160a9c4a9645b14bebbcfab71b50ef4
Bug 884634 - GTK3 port should use Linux theme. r=karlt
Bug 880590 - Remove _WIN64 define by configure. r=ted