When passing invalid parameters to a Slot's constructor it constructs empty slot now instead of throwing exception.
Comparison and assign slot operators check passing of the same object.
	modified:   prototype/Signals-test/src/Test.cpp
	modified:   prototype/Signals/src/signals/Slot.h
Comparison test for instance slots was added.
	modified:   prototype/Signals-test/src/Test.cpp
	modified:   prototype/Signals/src/signals/Slot.h