Adding first management command, to check data expectations / integrity
Merge branch 'develop' into dashboard_stats_1

Conflicts:
	kalite/settings.py
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 dashboard_stats_1

Conflicts:
	kalite/settings.py
Cleaning up settings, to only load apps as appropriate.
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
Merge branch 'update_language_tweaks' of github.com:bcipolli/ka-lite into release-0.11.1
Too much for one commit, but inseparable at this point.  Includes: localizing shared constants to shared/i18n, shortening names, decreasing non-debug output, closing file pointers when done, indenting changes, removing API keys from public code, and being explicit about language code formats.
Fix #1138 (move data files to internal data directory), fixed a copule of small bugs.
Validating languages, making internal storage for cache_subtitles use IETF standard, and django to use its own standard.
More refactoring, variable renaming, cleaning--and a few key changes to make use of lang_code (ietf vs django) more obvious and consistent
Merge branch 'release-0.11.1' of github.com:learningequality/ka-lite into lang_code_consistency
Merge branch 'release-0.11' of github.com:learningequality/ka-lite into lang_code_consistency
Fixing bug in branch code and in languagepackdownload code.