following transient_for. When TRAN_GROUP is found, Client.group will always
be !NULL. Some smart action should be taken using all members of the group in
this case.
+ Smart action idea:
+ Skip over members of the group that are also transients of the group
+ (have Client.transient_for set to TRAN_GROUP). These windows are not
+ ancestors and using them will also end up causing infinite loops!
When using coordinates/sizes of windows, make sure you use the right area. The
Client.area rect is the reference point and size of the *CLIENT* window. This