Bug 922460 - Kill media/webrtc/shared_libs.mk. r=ted

--HG--
rename : media/webrtc/shared_libs.mk => layout/media/webrtc/Makefile.in
Bug 925236 - Don't parallelize the libs and tools tiers because of the race conditions they show now they don't compile. r=gps
Bug 899808 - Fix matching of pseudo-elements in scoped style sheets. r=dbaron