Made interfaces for various aspects of retrieval that are Spring injectable.
Created an initial SBN retrieval task that will watch the /awips2/crawl directory, for proof of concept.
Amend:
Check whether debug is enabled prior to debug message.
Move log of request xml inside null check.
Change-Id: I5e3fe835f028cb93c98abce9735d3d59cfc663dc
Former-commit-id: 120296239cfa021507b4ce9bc3f7333509b1dfb9
Add GroupDefinition service.
Update subscriptions to not have a group name when their group is deleted.
Amend:
Rebase to HEAD of 13.2.1.
Change-Id: I817ca1912f76ccf347907ddb12e3f6fd8de7e5aa
Former-commit-id: 464b46dd4f4af60dbeb917f65c18c876d712e4ad
