1)	Fix some cases where -m wasn't being respected.
		file -m /lib/face/48x48x8/n/nemo.1
2)	Report on depth of p9bit files (including compressed).
		file /lib/face/*/p/pjw.1
3)	2 involved removing the string match for compressed images. This
	made exposed the fact that file wasn't handling depth<8 images
	properly. I've replaced the switch(d) in depthof() with a check
	for divisibility by/into 8, as per image(6).
4)	To preserve results, do ismung after isp9(bit,font).

In addition to 1 and 2, 3+4 make file's results more frequently
correct (no more things like "Ascii & Arabic text" on 4 bit
uncompressed images: see 'file /lib/face/48x48x4/r/rminnich.1').