Add "addition" statement and execution on assignement right part
	modified:   Definition/AbstractDefinition.php
	modified:   Definition/DefinitionInterface.php
	deleted:    Definition/Method/Add.php
	new file:   Definition/Operator/Add.php
	modified:   Definition/Operator/Set.php
	modified:   Runtime/Memory/ScripterMemory.php
	modified:   Runtime/RuntimeInterface.php
	modified:   Runtime/ScripterRuntime.php
	modified:   Tests/dirty/testFull.php