Bug 12091: HTML from auth_subfields_structure.tt doesn't pass firefox's html validator

Bug 12091: HTML from auth_subfields_structure.tt doesn't pass firefox's html validator

This cleans up the HTML in auth_subfields_structure.pl and
auth_subfields_structure.tt by:
- fixing some attributes
- removing some attributes
- and using a handy-dandy validation plug-in that Owen pointed
  me at the other day.

TEST PLAN
---------
 1) Install HTML Validator Plugin (Html Validator 0.9.5.8 Firefox addon)
 2) Log in to staff client
 3) Koha administration
 4) Authority types (on the right, 5 down from Catalog header)
 5) Click 'MARC structure' of any auth type
 6) Click 'subfields' (I believe for any Tag >= 010)
 7) Click 'Edit subfields'
 8) Right click and select 'View Page Source'
    -- Lots of HTML validation errors
 9) View the 'Authorized value:' and 'Thesaurus:' drop down lists.
    -- Patch cleans up code, so lists should remain unchanged
       after applying patch
10) Apply the patch
11) Refresh the page (make sure it isn't cached!)
12) Right click and select 'View Page Source'
    -- It should be down to 10 errors / 11 warnings.
       NOTE: I think this means there is a code problem with
             actually editing authorities properly!

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Work as described, much less validation errors, no koha-qa errors

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
CÃleans up code, also removes SQL in favor of using a method.
No regressions found.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>