New plots, new image analysis.

Too many changes for one commit, but oh well.

New plot showing where beams are pointed in far-field, using image of me
with knife in background. New plot showing distribution of number of
samples per pixel for a flat field image.

Updated vimg.m to not cut three particular detectors entirely, but rather
to only use the props file and the glitch algorithm. This required
updating a number of images, though I don't really see visible changes.
Don't scale plots from pfgplots! Figure placement

I seem to get better figure placement without using any options like
[th]
Fix bad reference
contrast diff is 1.7 K not 1.8 K
Spelling. Duplicates. A weasel.