Update for #941: set USE_L18N to True
decode dubbed video mapping from the central server as utf8
Merge pull request #1329 from aronasorman/1316

Encode youtube_id as utf-8.
Strip topic titles; should help with translations (specifically, with Science).

Conflicts:
	kalite/khanload/management/commands/khanload.py
	kalite/static/data/topics.json
Adding writeips.txt as a (data collection) script.
Adding absolute hack to get update command launching migrate via subprocess.
Force update to launch commands as external processes.

Conflicts:
	kalite/updates/management/commands/update.py
Adding KA-LITE-MOD markers
Solve #1323: refresh and store subtitles in the location where 0.10.2 servers can download & access them.  Also, make central and distributed server-accessible srt paths the same.

Conflicts:
	kalite/i18n/management/commands/cache_subtitles.py
	kalite/i18n/management/commands/update_language_packs.py
	kalite/shared/i18n.py
Only write files if some subtitle info has been changed; otherwise, skip those time-consuming steps.
Add client-side download code, fix bug.

Conflicts:
	kalite/updates/management/commands/languagepackdownload.py
Fix display of subtitles.

Conflicts:
	kalite/shared/i18n.py
Fix up computation and display of streaming online videos.

Conflicts:
	kalite/templates/homepage.html
	kalite/templates/topic.html
Fixing misc bugs hit during central server release.
cherrypy wasn't starting due to None CONTENT_ROOT; registration had an include & function call error

Conflicts:
	kalite/registration/views.py
Merge branch 'develop' of github.com:learningequality/ka-lite into 1316

Conflicts:
	kalite/i18n/management/commands/update_language_packs.py