This loader will abstract away the waiting for the controller to cleanup
the existing contents of the search mailbox
After some additional, to-be-done plumbing, I'd like
Controller.searchMessages to return some results info (like # of results
at the least) so that the SearchCursor returned can relay that
information to the client (which can then do a lot more interesting
things at that point).
Change-Id: Ifcba0ddf7170c56dac9f3b44128988a5aa4ca887
37c8a70d64