Major cleanup of CSS; deleting old cruft, and separating stuff out.
Further cleanup of unused CSS throughout the project.
Further cleanup, formatting, and organizing of CSS.
Enable tests modules to auto-import all test files in their directories.
making UserLog-related admin conditionally available, fixing whitespace (tab vs space) issue
copying out existing versioned-serializers code into shared/serializers/, adding into available serializers, doing proper imports and references.
cleanup from debug session that I missed in initial self-code-review.
point central-server production port to 8001 (8008 doesn't make sense, and we test way more than we release to a new server, so go to 8001)
Merge pull request #262 from bcipolli/user_log_admin

making UserLog-related admin conditionally available
rename 'version' to 'minversion' for versioned syncing
Merge pull request #264 from bcipolli/central_server_production_port

Central server production port
Merge branch 'develop', remote-tracking branch 'leq/develop' into develop
switch declaration CENTRAL_SERVER before declaring PRODUCTION_PORT
Merge pull request #279 from gimick/production_port_declaration

Production port declaration
Merge branch 'develop' of github.com:learningequality/ka-lite into save_the_django_serializers
cleaning cruft from django's serialize object
re-enabling fixture tests
Merge pull request #259 from bcipolli/root_urlconf

selecting urlconf conditionally; remove obsolete urls.py
Merge pull request #240 from jamalex/css_cleanup

Massive cleanup of CSS and related code
changing order slightly, to keep full_clean right with signing