Multiple fixes for DACS template, refs #5055

Squashed commit of the following:

commit add2f37fdeb657fb4ab71756ebccaecc16647285
Author: Jesús García Crespo <jesus@sevein.com>
Date:   Sat Sep 13 00:36:42 2014 +0000

    Add new event type in DACS

commit 2646ea4aa8bb4f8976f3ccda47d3ee2b7c89d6f6
Author: Jesús García Crespo <jesus@sevein.com>
Date:   Fri Sep 12 23:52:47 2014 +0000

    Add relatedMaterialDescriptions to DACS, refs #5055

commit 3ccd744e15e67957974a98a7be13f4138b1c73dc
Author: Jesús García Crespo <jesus@sevein.com>
Date:   Fri Sep 12 23:17:50 2014 +0000

    Add specialized notes to DACS

    Including custom taxonomy and terms plus its corresponding migration script.
    Rename the other notes field to "General note(s)".