Bugfix: Check that the submission's submitter exists before using it
Cleanups
Cleanups on properties
Goals: Add initial infrastructure

This adds a goal tab for TPs and allows creating and removing goals using
the same form and links that can be used for tags.

Fixes bug 3073
Goals: Add management command for adding project goals from a file

Fixes bug 3092
WORKING: Goal overview page

Fixes bug 3094