Fix for Bug 6602 - Reports dictionary doesn't properly recognize text columns

Fix for Bug 6602 - Reports dictionary doesn't properly recognize text columns

Reports dictionary won't let you set a comparison for MEDIUMTEXT columns. To
test, choose a MEDIUMTEXT column like borrowers.surname in Step 3 of adding
a new dictionary definition. Before the patch, in Step 4 you would not see
any kind of form field for entering a comparison. After patching Step 4 will
offer you a field labeled "Search string matches."

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Fixes described problem with mediumtext columns.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>