set Comment.variant.nullable=False
use Text.HEAD when variant is None in comments_sorted
Disable background queue delay in test configuration
Allow to use Shibboleth without set_display_name_on_register option

This fixes the functional shibboleth test.
Remove unneeded methods

These unneeded methods somehow made it into commit
03f382dac7e0248f221a94f51854c8f79191d961.
Fix proposal export if description is None
Add User.find_by_user_name classmethod

This is expected in lib.importexport._Transform._get_by_key.
Fix part of doctest root.rst
iframe overlays
dont allow nested overlays
document iframe overlays
rm background-color from body and #main as it is already set for html
make pager navigation navigate inside overlay
fix ret_url for comment reply form
cross browser height and width
Merge pull request #538 from xi/feature-fix-comment-ret_url

fix ret_url for comment reply form
Do not call apt-get update when -s is given (fixes #539)
Fix Membership.__repr__ for not yet commited objects
typos
rm flash_message, welcome_message and some others from overlays