Added message constants in Control, in order to support issue #4.
Added MouseEventHandler and MouseEventArgs for issue #4. Note that MouseEventArgs currently only exposes the fields of a MouseState.
Included MouseEventArgs and MouseEventHandler in the solution project.
Changed the internal representation of MouseEventArgs. This is no longer done using a MouseState, but instead a series of fields. The constructor is updated accordingly.
Added MouseMove event and OnMouseMove method to control.
Added sending MouseMove messages (#4) to controls from the ControlManagerBase.
Implemented handling of MOUSE_MOVE message (issue #4) in Control.
ListBox.IndexFromPoint now returns -1 if no item is available at the calculated index.
MouseEventArgs now uses an enum (MouseButtons) to describe which mouse button was involved in an event.
ControlManagerBase now supports messages for MouseDown/MouseUp/MouseClick (see issue #4) for all three mouse buttons.
Implemented mouse-event message handling and events for Control. MouseWheel not yet implemented.
Implemented a MouseWheel event (and message handling) which fixes #4.
Merge MouseEvents into master.