Add com.unknown.md content-type.

Not sure what registered that content-type, but the QL plugin needs to be listed in order to handle that situation.
Merge pull request #32 from booch/patch-1

Merged. Hopefully this will make progress on issue #25
Added .idea to gitignore
Make discount a real submodule
Migrated discount and adjusted config to be XCode only
Merge branch 'master' of github.com:toland/qlmarkdown into feature-discount-submodule

Conflicts:
	discount
Imrpoved discount updater

Changed discount updater to automatically checkout the submodule if
necessary. The old `update-discount.sh` file is no longer necessary,
so perhaps we'll remove it soon, but it's been left for posterity.
Fixed a silly path error on my part
More path fixes

I really shouldn't code at 1am
Cleaned up path code a bit
Updated readme to point to releases per #29