Added test implementation of interfaces in test_interfaces/
Added new CObject implementation (CObject_2 folder)
Due to problematic handling of single array of virtual methods and unsafe casting of void* pointers into function pointers
there are now structs of function pointers called interfaces:
	coIObject - including virtual destroy and toString methods
	IAudio - virtual play method
	IWidget - virtual mevent, draw, refresh, drag and setVisible methods

There are still problems:
	* index of interface struct pointer in class vtable is fixed (placed in IWidget.h for example)
	  thus additional care of that should be taken

	* derived classes must fill in not overriden methods with parent class virtual methods implementations
	  which should be done also very carefully

Now everything seems to work fine.