Roundtripping in EAC maintenanceNotes, fixes #3677

Squashed commit of the following:

commit d3647286209fe488e613ac7893083a3116dde656
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Tue Feb 19 04:37:20 2013 +0100

    Add revisionHistory and maintenanceNotes import

commit a2337b608b0ea387760c4debd2fcc05d06b734c3
Author: José Raddaoui Marín <raddaouimarin@gmail.com>
Date:   Tue Feb 19 03:51:57 2013 +0100

    Change revisionHistory and maintenanceNotes export