Update licenses for a bunch of casks

`git status` tells me it's 90 so I believe it.  Some notes:

- `mailpile` listed as `:oss` since it's either `:affero` or `:apache`
- `exhaust` listed as `:oss` since it's a custom license
- `shady` listed as `:oss` - Original creator indicates his software is licensed under a 'version' of the new BSD (see http://mattgemmell.com/license/), and is willing to license under BSD or GPL if desired.  The website (http://instinctivecode.com/shady/) claims to be open source but the link is dead (http://svn.cocoasourcecode.com/Shady/).  Github repo here: https://github.com/mattgemmell/Shady
- `gmail-notifr` listed as `:mit` - v0.9 is the last open version (https://github.com/ashchan/gmail-notifr-objc), but since v1.0 onward will only be offered through the App Store, this is open as far as we're concerned