Adds helpers for query columns selection.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11451 e93f8b46-1217-0410-a6f0-8f06a7374b81
Adds an helper for rendering query columns selection.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11452 e93f8b46-1217-0410-a6f0-8f06a7374b81