Fix ensure_dir: check that path is actually a directory path
Comment on ensure_dir function
Merge pull request #887 from b3b/develop

Fix ensure_dir: check that path is actually a directory path
Merge pull request #875 from dylanjbarth/bundle_subtitles

Bundle subtitles w/ language packs
Merge branch 'release-0.11' of github.com:learningequality/ka-lite into develop
Fixing up HTML to be compliant, according to http://validator.w3.org/
Merge branch 'release-0.11' of github.com:learningequality/ka-lite into develop
Merge pull request #1070 from bcipolli/khanload_update

Khanload & topic tree update
All apps should reference shared.topic_tools rather than main.topicdata, for fewer cross-app dependencies (and to avoid the main-specific, big computations in main.topicdata)
Central now needs gettext, since coach reports are localized.
Small cleanup items
Merge branch 'release-0.11.1' of github.com:learningequality/ka-lite into no_central_content_root
Get coach reports to work--had fouled up the url naming
Generalize the splat handler, to work for phase 2 (and not just KA topic tree)
Fixed some bugs with start and improved server stop
show options to go to previous or next exercise
added quotes and a small hack to give time to cronserver. Improved stop scripts.
missing quotes
small change when deleting files
fix #1242: check first if subtitles dir exists