This commit adds the feature of scaling region based on the zoom level of the monitor it is drawn on. The mentioned functionality is attained by using a map to maintain the handle of the region scale as per zoom level. The handle can then be obtained by the method win32_getHandle by passing the zoom information from the client.
The region object stores a history of all the operations performed on it
so that it can be used to create handles for different zoom level.
Additionally, this commit removes the public handle field from Region for win32 since
it is now replaced by win32_getHandle method for the clients and
internally the class uses a hashMap zoomToHandle to get the handle for
the particular zoomlevel. The default handle is stored in zoomToHandle
mapped to the initialZoom.

contributes #62 and #127