Bug 1002277 - TopmostJitActivationCompartment is not defined on non-ion builds. r=bhackett
Bug 945789 - Tune APZ physics prefs based on UX feedback. r=botond
Bug 1000736 - Throw a error if an app tries to record a video from a video file being transcoded into a stream. r=tterribe.
Bug 1001001 - Stop exporting opus_ symbols from libxul. r=rillian,ted

Opus doesn't seem to provide a define for being built as a static
library, but it allows us to override what it would define OPUS_EXPORT
to be.  So we can just define OPUS_EXPORT to the empty string and then
those symbols will be hidden in libxul just like anything else.