Fix for Bug 1883, authorised list of reasons why patron requesting book

Fix for Bug 1883, authorised list of reasons why patron requesting book

- Adding form controls to opac submission form and staf client
  edit form.
- Adding display of patron reason for suggestion on opac list
- Adding function for pulling an authorized value description
  using the category and value

TODO: Add some default authorised values

Signed-off-by: Colin Campbell <colin.campbell@ptfs-europe.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>