Adds "create drawing" interface, adjusts persistence and header/footer

This commit adds an interface for adding a drawing if none exist in the
database. This should also be usable for creating new drawings in the
future.

Additionally, some persistence bugs were ironed out (cascading) and
the site header and footer were tweaked.
Adjusts button bar on admin drawings list
Adds a view for editing a drawing. Fixes bugs.

This commit adds a view for editing individual drawings. It also
fixes bugs in the drawing views (e.g. wrong tier ids being inserted).
Adds methods for date formatting to the User model
Adds GUI for entering a lotto deposit