set window location

[chrisws]

If w.setsize(640,480) is used, the small window will always be made at the top left corner. Maybe it will be nice for SmallBASIC users to decide locations of windows. For example, w.setlocation(0,0) is at the top left corner and w.setlocation((XMAX-640)/2, (YMAX-480)/2) is in the central part. This new command may be quite useful for all of us.

see: https://www.syntaxbomb.com/index.php?topic=8000.0