Try to find out what causes a ruby bus error with ruby2.x on the CI server.

git-svn-id: http://svn.redmine.org/redmine/trunk@13743 e93f8b46-1217-0410-a6f0-8f06a7374b81
Use projects association.

git-svn-id: http://svn.redmine.org/redmine/trunk@13744 e93f8b46-1217-0410-a6f0-8f06a7374b81
Misc tests.

git-svn-id: http://svn.redmine.org/redmine/trunk@13745 e93f8b46-1217-0410-a6f0-8f06a7374b81
Droped legacy behaviour that allows a user to edit a few attributes of an issue without the edit_issues permission if a status transition is allowed (#15988).

Now that we can control permission on each field, this behaviour is no longer needed. The edit_issues permission is now required, which is consistent with the current requirements for bulk edition.

git-svn-id: http://svn.redmine.org/redmine/trunk@13746 e93f8b46-1217-0410-a6f0-8f06a7374b81