Update CHANGELOG (Version 0.20)
Emphasise public body categories upgrade step
Merge branch 'rails-3-develop' into release/0.20
Move up the config changes - they're important.

They'll result in changed behaviour if people don't act. Also, make
clearer what the previous default for INCOMING_EMAIL_PREFIX.
Merge branch 'rails-3-develop' into release/0.20
Bump Alaveteli version
Fix for interpolation bug introduced in 7a3b462f41321034cbdd2c83707f739a442e83c6.

The string with the unsubstituted variable pattern was being made
available for translation, instead of the translatable version.
Latest translations from Transifex
Restore translations lost in 3a412f2ec2c8f8c0a0eb5000791165ab82e7a550
Don't translate validation messages for models created/edited in admin interface
Merge branch 'release/0.20' into rails-3-develop