removed unused code
moved RandomCharField to otree.db.models
more cleanup
Merge branch 'master' of github.com:oTree-org/otree-core
error for session LCM: made more informative error message
Adding recreate management command.
Make recreate management command interactive by prompting if all data should be deleted.
Renaming recreate command to be resetdb.
Clean up checks

Errors will be grouped by issued function via ids
Fix checks for non-root games
Support apps with dots in their name during system checks.
Reorganizing forms modules into a common otree.forms package. Related to #258.
Using 'test' command for integration tests in .travis.yml instead of removed 'test_all'.
Merge branch 'master' of github.com:oTree-org/otree-core

Conflicts:
	otree/checks.py
Merge branch 'master' of github.com:oTree-org/otree-core into testimprovements
missing variabes on template now cna be tested with -t param on tests