Merge branch 'update_language_tweaks' of github.com:bcipolli/ka-lite into release-0.11.1
Multitude of fixes to central server pages and styling.
After server start, load a page silently to avoid a delay on first view

Will fail silently (without issue) if curl is not installed.
 branch 'release-0.11.1' of github.com:learningequality/ka-lite into release-0.11.1
Remove "parent" and "parents" from all code.
Remove exercises that are not "live" (there were 10), and tweak logging.
Topic tree updates
missed the module qualifier on NODE_CACHE
make sure default_language changes based on session
Solved problem for wrong node cache. Now, truly fixed!
Adding in switching of video language, based on urls
Tweaks to CachedPassword mechanisms, and decreased student iters on Pi.
Merge branch 'release-0.11.1' of github.com:learningequality/ka-lite into tweaks_from_nalanda_testing
Merge pull request #1143 from jamalex/landing_page_fixes

Multitude of fixes to central server pages and styling.
fixing bugs and code readability
Merge pull request #1151 from bcipolli/topic_tweaks

left-over code tweaks from cross-merge
Merge branch 'release-0.11.1' of github.com:learningequality/ka-lite into dubbed_video_choice
updates based on code review to eliminate loads(read()), tidy up docstrings, and be a bit more informative to the user with output.
test your code before submitting, Ben\!
Merge pull request #1140 from bcipolli/lang_code_consistency

Cleanup of i18n command code to make use of lang_code consistent