removed incorrect slot args handling for signal
signal handles slots with more args, still does not handle less. It would be faster to move this inspection from emit to connect
adding test for signal args and layout for socket_args_through_proxy_test
making signal require arg spec on creation and forcing slots to adhere to the spec on connect
attempt to prevent signal args from being mangled through proxy, need test for signal arg mangling, working on getting tests to pass
need way to inspect remote signals to get 'spec'
rewriting Signal to check function spec, updating pizco to use new signal (and fixing default 3 args when signal called through proxy
Agent.on_notification uses get w/default when getting notifications_callback. If unsubscribe is called, and the callback is removed the ioloop still seems to have a chance to receive a message, and try to call the now non-existent callback. Instead, default to the default notification callback
Merge branch 'develop' of https://github.com/hgrecco/pizco into develop

Conflicts:
	pizco/agent.py
	pizco/clientserver.py
	pizco/util.py
	tests/test_pizco.py
added last modification after rebase