Closes issue #1005.

- added support for the new Tigris bug tracker in the main website
- added basic documentation about how to develop and test new bug trackers
- updated documentation, based on review comments
Merge branch 'master' into issue1005

Conflicts:
	mysite/project/templates/edit_project.html
Remove deprecated kwarg
Merge pull request #313 from ehashman/issue1005

[issue1005] Support for new Tigris bug tracker in main website