Bug 10853: Add DB field export_format.type ('marc' or 'sql').

Bug 10853: Add DB field export_format.type ('marc' or 'sql').

This patch:
- adds a new column 'type' to the export_format table.
- renames the field name export_format.marcfields with
  export_format.content.

Test plan:
- Check that existing profiles have the type "marc" selected by default
- Create a new profile with a type "sql"
- Save and verify the profile is correctly displayed when you select it.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Comment: Work as described. koha-qa reports Small tabs errors,
corrected in followup

Test:
1) go to Tools > CSV profiles, Create profile, current
2) Apply patch, run updatedatabase
3) Go to Tools > CSV profiles, new option present
old profile with type MARC
4) Create new profile MARC, save and show correct
5) Create new profile SQL, save and show correct

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
All tests and QA script pass with all 3 patches applied.
Works as described. Functionality for SQL profiles will be
added by another patch. For now it's possible to add/edit/delete
them.
Existing CSV profiles can still be exported correctly.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>