Misspellings run

Based on:
  misspellings $(find * -type f \! -name '*.png' \! -name '*.xcf')

This is a tool I use for spell checking source code. I was curious how
it would do on math/tex. Mostly false positives, but the following
three valid hits.
Merge pull request #291 from lyda/mispellings

Misspellings run