Move vim ruler to column 81

Most of the time my terminal is 80 characters wide, so it's obvious when
I've run over.
Ignore Thumbs.db

Copying files back and forth from Windows machine results in these
things strewn all over the place, like DS_Store in OSX.
Limit 'yesterday' function to two dirs deep

It's simpler to just search everything, but it can get very slow when
there's e.g. a vendored rails/rails master gem lurking in there. This is
a hack, but all of my actual work is in ~/projects.