Adjusts the x/y co-ords of an ILBM's BMHD.
I created this tool when I discovered that DeluxePaint(tm)
sets this to zero on write and ignores on reads.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO METHOD CRC     STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]               115700  268148  43.1% -lh1- 0d01 Jun 30  1996 BrushXY
[generic]                 4887   13609  35.9% -lh1- dcf1 Jun 30  1996 BrushXY.guide
[generic]                  247     501  49.3% -lh1- e42b Jun 30  1996 BrushXY.guide.info
[generic]                  253     518  48.8% -lh1- 20f9 Jun 30  1996 BrushXY.info
[generic]                 4303   10516  40.9% -lh1- a4be Jun 30  1996 BrushXY.txt
[generic]                  333     835  39.9% -lh1- 9365 Jun 30  1996 BrushXY.txt.info
[generic]                31657   37022  85.5% -lh1- 445d Jun 30  1996 diver.pic
[generic]                  280     466  60.1% -lh1- 4d9e Jun 30  1996 diver.pic.info
[generic]                 8447   11228  75.2% -lh1- 9761 Jun 30  1996 diver1.win
[generic]                  149     242  61.6% -lh1- e783 Jun 30  1996 diver1.win.info
[generic]                 8445   11216  75.3% -lh1- 27dc Jun 30  1996 diver2.win
[generic]                  233     476  48.9% -lh1- fedd Jun 30  1996 diver2.win.info
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total        12 files  174934  354777  49.3%            Jul  2  1996