@heff fixed a code bug in track XHR requests. closes #1715
Release 4.11.1
Merge branch 'stable'

Conflicts:
	dist/video-js/video-js.css
	dist/video-js/video-js.min.css
	dist/video-js/video.dev.js
	dist/video-js/video.js
@PeterDaveHello added a Traditional Chinese translation. closes #1729
Support native captions in html5 tech.
Don't auto-add the textTrackDisplay component.
Add a 'featuresNativeTrack'. Currently hardcoded to false for everything
except the html5 tech.
Add textTracks and addTextTrack methods to html5 tech.
Proxy player level methods to tech if we're using native tracks.
Fix up track menu items to work with spec tracks or vjs tracks.
Re-add text tracks on 'movingMediaElementInDOM'
Use custom tracks if no native textTracks support
Also, if text tracks are old and use numerical mode values, use custom
tracks.
If an html tech is using custom tracks, remove track elements so we
don't accidentally show both custom and native captions.
Clean up showTextTrack slightly.
Use setAttribute and 'in' so IE8 doesn't feak out.
Firefox gets custom captions for now
Move as much as possible into techs.
textTracks is completely inside of techs but needs to be called manually
because techGet requires the tech to be ready.
addTextTrack, unfortunately, currently forks. If when called, it doesn't
have a tech, it assumes that it's a custom implementation and does the
same work that MediaTechController#addTextTrack does.
Don't create a flash getter for textTracks.
Fix tests. Assume native text tracks, intially
Add tracks to texttrackdisplay on ready
Add tracks buttons async
Create custom tracks with the correct player
Move addTextTrack fully into techs.
Load up textTrackDisplay synchronously but have it do no work until the
player is ready (see the previous commit).
Move controlbar addition into player
In Html5, support tech, support non native tracks
Add a check that delegates to MediaTechController's methods if we're in
Html5 but we are not using native tracks.
Add an 'update' method to menu
Move tracks buttons to controlbar children
Update tracks buttons if needed