SQLite does not support case insensitive match for non-ASCII characters (#18537).

git-svn-id: http://svn.redmine.org/redmine/trunk@13760 e93f8b46-1217-0410-a6f0-8f06a7374b81
Missing test helper (#18537).

git-svn-id: http://svn.redmine.org/redmine/trunk@13761 e93f8b46-1217-0410-a6f0-8f06a7374b81