Bug 849958 - Add primitive axis-locking code to dynamic toolbar. r=kats

Add some axis-locking code that adds a scroll threshold to toolbar appearance,
and stops the toolbar from appearing when scrolling down then up when the
toolbar isn't visible, or when scrolling side to side.
Bug 849845 - Map Gamepad L1/R1 to back/forward on Android. r=kats
Bug 779291: Implement SPS stackwalk using the breakpad unwinder. r=bgirard,glandium
bug 850089 - fix SPS with disable-crashreporter. Patch by Ted Mielczarek <ted@mielczarek.org>, r=glandium
Bug 850132 - SPS breakpad unwind (bug 779291) breaks Win64 builds with "Unsupported platform". Patch by Makoto Kato <m_kato@ga2.so-net.ne.jp>, r=ted