Added a cross-project issue list. It displays the issues of all the projects visible...

Added a cross-project issue list. It displays the issues of all the projects visible by the user.
The users list available in the filters ('assigned to' / 'created by') is made of the members of all projects the current user belongs to.
For now, this view is only accessible from 'My page' ('issues assigned to me' or 'issues reported by me' blocks, to view the full lists)

On 'My page', assigned issue are now sorted by priority.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@684 e93f8b46-1217-0410-a6f0-8f06a7374b81