Added time_start and time_end parser and checker.
Fixed missing datetime import.
Consolidated ng js files into a single flask view.
Renamed addrule/host calls to save.
Successful 'save' now clears 'new' object for rules and hosts.

Also, exiting record is marked in red text if being edited (known because '_uid's match).

This fixes problem where making consecutive edits appeared to create new records, but actually were overwriting the first one because the _uid never changed.
updated version and README.
Updated version (again?).