Bug 20689: (follow-up) Make it possible to add capital letter subfields to item searc...

Bug 20689: (follow-up) Make it possible to add capital letter subfields to item search fields

This patch adds some custom validation to the MARC tag and subfield
fields so that they are limited to alphanumeric characters.

Both templates (the main view and the edit view) have been modified so
that item_search_fields.js can be included in both.

To test, apply the patch and test the form by entering a variety of
different character combinations. The "MARC field" and "MARC subfield"
inputs should only accept alphanumeric entries.

Test both "new" and "edit" operations.
Test other operations like delete and cancel.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jose-Mario <jose-mario.monteiro-santos@inLibro.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>