Feature/rails3 fix pagination

fixes #1371 and #1409 on openproject.org

* #1371 - when changing items per page in the pagination links, page is now set to 1 (so we dont land on an empty or unexpected page)
* #1409 - when coming from the projects setting page and clicking on members and then chaning pagination, we now get a new page on the members tab (not the general settings tab anymore)
* added/fixed a possible path for our cukes to reach the general project settings page