Changed the "drop" behavior for the FXColorWell widget. Previously, dragging a color swatch over a color well caused the color well to emit SEL_CHANGED messages. If a drop followed, however, no SEL_COMMAND message was being sent to the color well's message target. This inconsistency caused programs which only trapped SEL_COMMAND to behave oddly. Now, the FXColorWell widget does send a SEL_COMMAND message when the color is dropped, and the color does not change while dragging over it.