adding a command-line utility for executing common testing functions
missing delete function on config.
new katest management command "clean_db"
preventing central-server regret
refactor confirm logic in katest clean_db
Merge remote-tracking branch 'gimick/katest_tool' into katest_tool

Conflicts:
	kalite/management/commands/katest.py
Don't allow people to be invited to headless zones, nor to create any.
use a separate (memory-based) cache for sessions
don't let topic tree collapse when it's empty; always display 'None' for 'selected topics' when empty
hide the form element for adding a group to a teacher, also disable :)
previous checks on whether caching is enabled now fail.  Fixing to check CACHE_TIME instead.
Merge branch 'software-keyboard' of git://github.com/jamalex/ka-lite into software-keyboard

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Signed-off-by: wangguan59 <wangguan59@gmail.com>
Windows script will now pull the production port.
Fixed the top navigation bar hover problem. Clean up some code in Khan-site and moved to Khan-lite, and group nav css together.
Moved JS from exercise.html/video.html
Removed delimiter.
update
update in video.html
Modify the code format, and make install link open in external window
sessions cache uses default cache only.  webpage cache can use named cache. so, migrate to this.