Converse term changes, refs #6049

Use relations table instead of a column in the term table
to set converse term relations. Fix EAC cpfRelationType export

Squashed commit of the following:

commit 5eddd48a3c792eaa7367ca2e8220e2582791dc42
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Sun Dec 8 23:53:54 2013 +0100

    Change EAC cpfRelationType export

commit 4addfac3aca6a2969c4baabc2a0f4d970e80e27d
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Sun Dec 8 23:10:26 2013 +0100

    Change subType field in ISAAR relations

    Use converse term relations instead of converse term column

commit 0736028e1d9928dd539028ad50b53d9309a79f2f
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Sun Dec 8 21:35:07 2013 +0100

    Change converse term relation in term pages

commit f43962bb1d6c64abf99132fcd5f60940913714b7
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Sun Dec 8 18:54:38 2013 +0100

    Change version value in fixtures

commit a45a9902deffbf951a969a00d6c085d48410281c
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Sat Dec 7 09:17:07 2013 +0100

    Change data model for converse terms

    Remove column (schema, sql, model), create new terms and
    relations via migration script and fixtures