Bug 770625 - Use the same compiler for b2g desktop builds as desktop linux. r=ted
Bug 894242 - Make C++0x/C++11 mode of gcc/clang mandatory. r=ted
Backed out changeset 6846b610be41 (bug 897409) for suspicion of making Win8 mochitest-mc perma-orange.
Merge build-system into inbound

--HG--
extra : rebase_source : 134f61ef25a1472f98b40b07069fbb7e8f9d8b63