Bug 941145 - Rename goUrl to get for WebDriver compatibility. r=dburns
Bug 962288 - Don't call DeprecatedGetAsSurface unless it's Cairo. r=mattwoodrow

Changeset from Bug 959123 caused a performance decrease because
DeprecatedGetAsSurface was being called on an image that may not
be a CAIRO_SURFACE.

Reverted CairoImage surface members to public access as they were
before the patch from bug 959123.
Bug 962896 - Add source address to STUN logging. r=bwc