fix bug 873327 - use *compiled* librabbitmq
Fix bug 869480 and bug 809495: infrastructure for user bans.

This is a simple model for user bans, and a middleware which enforces
them. The middleware will log out any request from a banned user, and
show them a page which can explain that they're banned, and show the
reason for the ban, before letting them proceed to their requested
page.

A simple user-banning view (keyed off permission to create the UserBan
model) is also included, collecting appropriate details on who issued
the ban and why.
Merge pull request #1108 from ubernostrum/ban-middleware-869480

Fix bug 869480 and bug 809495: infrastructure for user bans.
Admin interface for user bans should use raw_id_fields instead of loading all the users.
Use explicit related-lookup syntax in ban search.
Merge pull request #1121 from ubernostrum/ban-middleware-869480

Admin interface for user bans should use raw_id_fields
Merge pull request #1117 from groovecoder/librabbitmq-compiled-873327

fix bug 873327 - use *compiled* librabbitmq
Set licence to MPL 2.