Merge pull request #2254 from learningequality/release-0.12.0

Release 0.12.2
Fix for #356

Usernames are truncated if longer than max-width.
Using vw instead of em in caption sizes

vw allows for more responsive text design because it changes the font-size based on the size of the viewport. (1vw = 1% viewport width.)
Using vw instead of em in caption sizes

vw allows for more responsive text design because it changes the font-size based on the size of the viewport. (1vw = 1% viewport width.)
Fix for overflowing buttons in Update Videos page

This > https://i.imgur.com/NrJ28jA.png
Hot fix for #1985 to make `generaterealdata` management command work.
Hot fix to pass Travis tests by checking that `lang_name` has a value for dubbed video data on `get_dubbed_video_map()`.
Also includes hot fix related to #1253.
This overrides the previous commits os similar-named branch to cherry-pick final codes to remove the debug commits.
Remove hot fix because json is fixed on central server.
Merge pull request #2270 from cpauya/feature/1985-generaterealdata-fails-in-model-generation-2

Hot fix for #1985 to make `generaterealdata` management command work.
Merge branch 'master' of github.com:learningequality/ka-lite into release-0.12.0
Update video-js.css

Fallback for vw
Update video-js.css

Fallback for vw
Update khan-lite.css

Added the missing white-space property and a vertical-align hack-fix for IE6 & IE7

One more thing, since IE6 doesn't support min-height and max-height, max-height is treated as height.
Merge PR #2264 into release-0.12.0

Conflicts:
	kalite/distributed/static/css/distributed/khan-lite.css
Merge branch 'release-0.12.0' of github.com:learningequality/ka-lite into nalanda-rct2

Conflicts:
	kalite/distributed/static/css/distributed/khan-lite.css