Diminish yasnippet and autopair modes

I almost always turn them on and off programatically, so I don't need to
see them in my modeline.

Note that diminish.el is installed by way of package.el, into the elpa/
directory, which I am keeping under version control. Some would argue
against so doing, but I prefer the stability of having every package I
use for my editing under VC.

Yes, it adds some weight, and it may prove to be a bit of a pain, but it
also means I don't have to worry about packages that were once
publically available vanishing out from under my config.