Firstly, you need to fetch the submodules:
git submodule init
git submodule update
Now everything will compile.
The minimalist branch has a number of features removed, and may interest you.
This client can mediate scrobbles from multiple clients. It has a fully featured Applescript interface to allow this. However currently Last.fm's user page will always say "iTunes" as the player. This is because even though we wrote this awesome mediating interface, we only use iTunes with it so never mind eh?