Merge dashboard & search modes into browse mode
[NX-222] Repositories Ui
testing serializers
Merge branch 'master' into blobstore-refinements
Use file instead of path, easier.  Expose the file, use name of directory as part of filename for clarity.
Drop use of multimap, too complex, just use a treeset for state mgmt.
Hacked in copy to get tests working, keys and values for mapdb bits need to be immutable.
Add test of basic state tracking.
Move logging outside of tx context where possible.
Add note about exposing transactional context with snapshot to avoid pre-building list of blobids