Refactor: use an ordered hash to store available filters and remove :order option (#13154).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11372 e93f8b46-1217-0410-a6f0-8f06a7374b81
Adds SQL server example and cleanup.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11373 e93f8b46-1217-0410-a6f0-8f06a7374b81