Began making cell utils cleaner.
Began renewed push to finish draft of `NTorFSM`.
Merge branch 'cleaner_cell_utils' into ntorfsm

Conflicts:
	oppy/cell/util.py
Merge branch 'cleaner_cell_utils' into ntorfsm

Conflicts:
	oppy/circuit/handshake/ntorfsm.py
Finished drafting `NTorHandshake`.
Added better error reporting in `OnionCircuit`.
Squashing bugs in `crypto` and `NTorFSM`.
Trying to send `RelayExtend2Cell`.
added missing methods to encryptedrelaycell
Made `manager.py` test use a cached consensus file.
Now caching server descriptors for debugging.