Added showing/hiding of the toolbar (ref #305).
Added auto-showing toolbar when debugging starts (ref #305).
Changed order of stopping debugger and saving settings (ref #305).

Need to stop the debugger first as it changes some of the UI elements
(toolbar visibility, tab names, stack/watch windows) so that the correst
state is saved.
Added a workaround for wxwdigets bug when toolbar is shown (ref #305).

When the toolbar is shown after being initially hidden (with the main
window being maximized), it leaves a small artifact on the toolbar.
This workaround removes the artifact.
Added showing/hiding of the status bar (ref #305).
Added a workaround for wxwdigets bug when status bar is shown (ref #305).

When the status bar is shown after being initially hidden, it draws the
content of the status bar in the wrong location. This workaround fixes that.
Removed a workaround on OSX that is no longer needed.
Fixed status/toolbar visibility on exiting full screen mode on OSX (ref #305).
Disabled showing hidden toolbar while in full screen mode (ref #305).

The toolbar is drawn with artifacts on the screen in Windows, so it's
disabled for not until fixed in wxwidgets.