Squashware Doom v1.3

• Separate DOOF install images are now generated for 5.25" 1.2M and 3.25" 1.44M floppy disks. This fixes problems with the previous version where doof.img would not boot if written onto a 1.44M disk.
• There is no longer separate doof.img and doofboot.img floppy images. Both floppy disk images (now targeting different physical formats) are both now bootable.
• Some graphics have been made smaller using a lossy compression technique to merge similar-looking columns. The results were applied selectively and judiciously to ensure there was no serious effect on quality.
• There is now a vanity ENDOOM lump.