Bug 881432 - Add webvtt_strerror to exports. r=bustage.

CLOSED TREE approval from RyanVM.
Bug 877124 - [AccessFu] Trust explicitly associated names of the current pivot and its children. r=eeejay
Bug 877124 - [AccessFu] tests for the trusted explicitly associated names for children of the current pivot. r=eeejay
bug 879802 - Clean up the #includes in the WebGL implementation - r=bjacob
Bug 879952 - OES_texture_float should not allow linear filtering - r=bjacob
Bug 879954 - Implement OES_texture_float_linear - r=bjacob