* updates: cleanup, caching accounts, refactoring and work on

* updates: cleanup, caching accounts, refactoring and work on
   the send-queue (not working yet)

* modest-tny-account, tny-account-store:
	- refactory, move account creation to modest-tny-account

* modest-tny-account-store:
	- cache accounts; add functions for retrieving tnyaccounts
	 corresponding to account-mgr accounts

* modest-tny-send-queue:
	- fix some bugs, getting much further now

* cleanups, cosmetics

pmo-trunk-r790