Added paths for getting all artists and albums on the server side.

You will have to run `go get -u github.com/dkuntz2/gompd/mpd` in order to be
able to run again.

I'm hoping that we can create a more real library instead of just listing all
of our songs. This may also help with the big libraries not working well.
Merge branch 'master' of github.com:turbowookie/turbo-wookie

Conflicts:
	backend/turbo-wookie/TWMPDClient.go