CONFIGARGS:  Include the monitor name

Augment the CONFIGARGS macro to also include the monitor name of the
configured window.
Ident:  Print monitor name selected window is on

When using Ident to show information about a window, also print out the name
of the monitor.
Merge branch 'ta/various-monitor-fixes' of github.com:ThomasAdam/mvwm into ta/various-monitor-fixes
Deprecate FindScreenOfXY()

Move the functionality to monitor_by_xy() instead, and switch over the
callers of FindScreenOfXY to it.  Reduces the need for a transient function
serving no purpose.