Draft: Refactor context menu
Move the window actions out of the context menu. They are not directly related to the entire group, and some users don't want them.
To retain access to the window actions, they are added to the to the window list menu and as an option for the middle mouse button on the group.
I'm not sure if all the changes to the glade ui file are strictly necessary. The version I used wants to change all the properties from some_thing to some-thing and add a bunch of placeholder elements.
Edited by David Keogh