Allow in-place editing of metadata fields

[rosiel]

It would be nice to allow metadata to be edited in place, rather than having to go into a form (i.e. one built with XML Form Builder).

[rosiel]

I think there are too many problems in implementing this for complex metadata. Anything complex like MODS gets extracted from its XML structure when it's presented to the user, extracted by xpath directly or indirectly through Solr. Since most fields allow multiple values, it would be very challenging to "undo" the crosswalk to track exactly which node in the XML needs to be edited.

A simple, flat metadata structure such as DC would be more amenable to this.

My vote, as we tend to default to complex structure like MODS, is to leave this as "too hard to fix" unless some brave person desires.