Automatically make docky semi transparent when inactive

Automatically make docky semi transparent when it is inactive, to maximise use of the screen.

Docky takes up too much screen space when the "Allow window overlay" and "Automatically hide" options are both off. With "Allow window overlay" on Docky often obscures the bottom of maximised windows - a real annoyance when using the terminal, for instance. With "Automatically hide" on it isn't possible to glance at Docky, and it takes longer to use it because icons aren't visible until the pointer is moved to the bottom of the screen.

Making Docky semi transparent when overlaid on top of other windows and not in use could maximise the use of screen real estate without significantly obscuring other windows or adversely affecting the user interface. Docky would remain opaque when the mouse moves over it and when it isn't overlaid over other windows. The transparency level could be configurable (as a percentage) to suit user tastes.

A further associated option could be to shrink Docky while transparent, or instead of making it transparent. The standard and shrunk sizes could also be configurable (as a percentage of the default size) to suit user tastes.

This is an alternative solution to the "add an option to keep the dock behind the active window." blueprint.