Unwanted layers control

LMap.addLayers allows layers to be added to a map without having a Layers Control created and displayed.

However, removing a layer by calling LMap.removeComponent causes a Layers Control to be created and displayed on the map.

This update allows the caller to control whether the default Layers Control should be created or not by checking a flag in the getLayersControl method.  The flag defaults to true so as not to impact existing code.  It can be set via a new constructor or a setter.