Don't limit number of templates shown in the 'Create Document' menu
I don't think there's really a good reason to limit the size of the menu. If a user wants to put lots of things in it, that's their choice, and they can fix it easily enough if they don't like the large menu. (Also, Thunar does not have this limit.)
Not showing them all makes people think xfdesktop is buggy, or at the very least just causes confusion.
Closes #398