Edit Color Map Toolbar button should toggle the Color Map Editor
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
Now that the Color Map Editor is a dockable window, I suggest we modify the behavior of the Edit Color Map toolbar button to be a toggle for showing and hiding the editor. This is partially to make it more consistent with the other GUI controls such as the view menu items controlling dockable windows as well as other GUI elements that can be shown or hidden, but it is mostly because I often frequently turn the color map editor on and off (it takes up a lot of room), and it would be much easier if there were one click target to turn it on and off rather than separate click targets to turn it on (the toolbar button) and off (the x in the dockable window).