Aleph data

A number of fields have been added. To include support for some of them I've revised everything from oaimarc2slimmarc.xsl to the datastreams Mods, WorkMetadata and InstanceMetadata. i.e., both xslt and ruby.

The work_controller and instance_controller now works with the aleph import services, such that forms are prepopulated. I.e., this should complete the user story. There are opportunities for polishing, however.

/Sigge
Improved the corresponding code in instance_controller