[action] added new protocol which "superset" RBThenable
[promise] use RBAction object instead of custom attributes
[promise] introduce a 2nd state on RBPromise which is a more global one than "state"
[promise] perform actions only if promise resolve state is not set to RBPromiseResolveStateNotReady
[tests] update RBPromise tests to match with new API
Merge branch 'development' into action-syntax

Conflicts:
	Rebelle/RBPromise.m
	RebelleTests/RBPromiseTests.m
[tests] reverted tests to resolver branch version
[promise] change ready() implementation + call executer on ready if promise resolver finished
[project] renamed classes
[promise] add next() method
[action] added tests for actions
[promise] updated tests + new tests about ready() method
[promise] fire ready() automatically after delay
[promise] call setters into dealloc to remove KVOs
[action] added test on exceptions
[executer] factorized RBExecuter to use RBActionSet
[project] updated pbx
Merge pull request #9 from KptainO/action-syntax

Alternative callback syntax