Adds the ability to move threads between project forums (#2452). 'Edit message' permission is required.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2649 e93f8b46-1217-0410-a6f0-8f06a7374b81

Adds permissions to let users edit and/or delete their messages (#854, patch by Markus Knittig with slight changes).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2019 e93f8b46-1217-0410-a6f0-8f06a7374b81

Users who create/reply a topic are automatically added as watchers but are now able to unwatch the topic.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1878 e93f8b46-1217-0410-a6f0-8f06a7374b81

* messages can now be edited/deleted (explicit permissions need to be given)
* topics can be locked so that no reply can be added (only by users allowed to edit messages)
* topics can be marked as sticky so that they always appear at the top of the list (only by users allowed to edit messages)

git-svn-id: http://redmine.rubyforge.org/svn/trunk@926 e93f8b46-1217-0410-a6f0-8f06a7374b81

Permissions for forums management can be set in "Admin -> Roles & Permissions".
Forums can be created on the project settings screen ("Forums" tab).
Once a project has a forum, a "Forums" link appears in the project menu.
For now, posting messages in forums requires to be logged in. Files can be attached to messages.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@529 e93f8b46-1217-0410-a6f0-8f06a7374b81