Commit partial updates so I can merge upstream changes.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	extensions/index.html
	extensions/proposals/WEBGL_dynamic_texture/index.html
Support for typedefs
Merge branch 'newtypes' of https://github.com/dsheets/WebGL
Major update, exposing streams and supporting presentation time of video frames.
Merge pull request #320 from msc-hi/master

Major update to WEBGL_dynamic_texture.