Add Open and Close channel transitions
Introduce @NetzobLogger decorator.

This decorator automatically attach a self._logger instance configurer for the
current class. It also create a __getstate__ and __setstate __ to remove the logger
from the serialization process (pickling).
More work on the implementation of the abstract state.
Some work on the state.
Work on the AbstractTranstion like supporting priorities between transitions.
Usable version of the OpenChannelTransition and CloseChannelTransition.
Implement executeAsInitiator and executeAsNotInitiator methods.
ASCII() takes a RAW as value in the constructor
Fix doctests
Size in types constructors must be converted in bits
Implement getCells on AbstractField.
Upgrade variables.

Sorry for this short commit msg.
Add vocabulary in AbstractVariableProcessingToken.
Upgrade doctests in Field.
Add metadata in messages
Add messages in Symbol definition
Update the __init__ files
Add new doc tests
register usbMouseProtocol test
Fix various bug in NetzobRegex and add a builder for a default Regex.