Release V2.3

More bug fixes. Big thank you to @cator for his help identifying the remaining problems..

This revision fixes an issue that can occur if the Alibre user profile contains 'broken' shortcuts. By 'broken', I mean shortcuts that are declared but have no associated keycode. It is not clear how these 'broken' shortcuts get into the user profile but I suspect it is because a user initially sets a shortcut and then subsequently deletes the same shortcut using the Alibre System Options.