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.
[VMC] - Teapot and Framerate counter do not appear on the WebGL+CSS test site on Chrome dev.
https://code.google.com/p/chromium/issues/detail?id=259817

Fixed mismatched uniform precisions between vertex and fragment shaders causing demos to fail to load in Chrome on Windows. The conformance test glsl/misc/shader-with-global-variable-precision-mismatch.html (currently failing on some platforms in Chrome) already covers this case.
Merge pull request #322 from kenrussell/mediump

[VMC] - Teapot and Framerate counter do not appear on the WebGL+CSS test...