Add converse predicates to ISAAR relationships

- Add converse_term_id column to terms table
- Create new actor relations terms with converse term
- Add converse term field to term edit and index pages
- Add subtype field to ISAAR relationships
- Improve edit term relationships area
- Fixes #6049

Squashed commit of the following:

commit 0c3630b560aa068df4a0ce5ebab24ab506c690ad
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Mon Dec 2 06:01:32 2013 +0100

    Improve term relationships section

    Add taxonomy and/or parent field to the parent, relatedTerms
    and converseTerm fields autocomplete request

commit 051a01b469ea3bb1502e755af5bdd2b856557285
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Mon Dec 2 03:25:19 2013 +0100

    Fix relations for subjects

    Load and save converseTerm in the type if exists

commit 8ac2a530b93211286f6fffa5eadfb2feb323dd1b
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Mon Dec 2 03:16:48 2013 +0100

    Improve javascript for subtype field

    Fix data load, change generateRequest method for subType field
    instead of reboulding the field

commit 57bf487c1f54d3e0301137a7937039dcdcb74d73
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Mon Dec 2 03:09:10 2013 +0100

    Add subType values to relation index data

commit fa9154672c088d6de359ad1d5cd2e4ae3b8a9a20
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Fri Nov 29 00:47:06 2013 +0100

    Changes in dialog.js

    Enable/disable relationship type in the related actors dialog
    and change the autocomplete URL depending on the category

commit e7465b814205e2457a526872890219ed0c6b404a
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Fri Nov 29 00:44:35 2013 +0100

    Add 'Relationship type' field

    In the ISAAR edit page (dialog and table) and in the index page.
    Allows to set category and type of relationship, showing the converse
    term for the type in the related actor

commit 665f1a4dee93e69e7338515221c8b0681705fc7a
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Thu Nov 28 20:33:07 2013 +0100

    More term autocomplete changes

    Allows to filter by parent being outside the term module

commit 2864650ef8b8cfd3a7999283019a4cb30db1e02b
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Thu Nov 28 20:30:16 2013 +0100

    Change column name for converse term

commit c34ab12f36bae0cf024a36c88fc4dd6c9698463a
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Wed Nov 27 11:41:04 2013 +0100

    Add reciprocal term field in term pages

commit 4f97f4abd3fd54979fdecfccec64e05a6494959b
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Wed Nov 27 11:39:08 2013 +0100

    Term autocomplete tweaks

    Fix exclude the calling object and it's descendants from the list,
    add option to filter by parent and add 'self-reciprocal' option
    for reciprocal term autocomplete

commit a6eac127e8aad51669d3673a5078eb2ccd790c9c
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Tue Nov 26 03:18:46 2013 +0100

    Add reciprocal terms for actor relations

    Add 'reciprocal_id' column in the term table and create new terms
    via migration script and in the sfInstall loadData() method