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.
Only write files if some subtitle info has been changed; otherwise, skip those time-consuming steps.
Add client-side download code, fix bug.
Fix display of subtitles.
Fix up computation and display of streaming online videos.
Strip topic titles; should help with translations (specifically, with Science).
Don't show i18n language-changing, nor language pack management link
Fixing misc bugs hit during central server release.
cherrypy wasn't starting due to None CONTENT_ROOT; registration had an include & function call error
Merge pull request #1339 from bcipolli/release_bugs_1

Fixing misc bugs hit during central server release.
Merge pull request #1337 from bcipolli/1323

Update subtitles paths on central and distributed servers, to be consistent with past versions (and each other)
Merge pull request #1338 from bcipolli/fix_streaming

Fix up computation and display of streaming online videos.
Fix seek method to work for video.js (and renamed from seekTo).