a little progress on the match set editor:

a little progress on the match set editor:

now we can retrieve a tree from the server and use it as the basis of
our dijit.Tree widget. Still work to be done. Can't save anything yet.

Note to self: borrow dojo dnd's "copy" operation (as opposed to move) to
mean replacing a node in the tree, rather than adding to the tree.

Re the permissions I changed, actual users of Evergreen hate having as
much granularity as there was before, and it just confuses people trying
to figure out what perms to give to whom.

Note to self 2: add ADMIN_IMPORT_MATCH_SET to ppl