makefile: Fix install target, and various cleanups
makefile: Fix install target, and various cleanups

quilt/quilt,mmussomele/quilt,tejasmanohar/quilt,NetSys/quilt,kelda/kelda,kklin/kelda,kklin/kelda,NetSys/quilt,secant/quilt,mmussomele/quilt,kayousterhout/quilt,akshayknarayan/quilt,akshayknarayan/quilt,kelda/kelda,kklin/kelda,kklin/quilt,kklin/quilt,secant/quilt,secant/quilt,PenguinToast/quilt,kayousterhout/quilt,ejj/quilt-dev,akshayknarayan/quilt,quilt/quilt,NetSys/quilt,PenguinToast/quilt,NetSys/quilt,kklin/quilt,mmussomele/quilt,mmussomele/quilt,kayousterhout/quilt,stevenlin598/quilt,quilt/quilt,PenguinToast/quilt,PenguinToast/quilt,ejj/quilt-dev,ZhongtianWang/quilt,ZhongtianWang/quilt,ZhongtianWang/quilt,kayousterhout/quilt,akshayknarayan/quilt,tejasmanohar/quilt,kelda/kelda,kelda/kelda,NetSys/quilt,PenguinToast/quilt,mmussomele/quilt,LuiseV/quilt,LuiseV/quilt,quilt/quilt,stevenlin598/quilt,ZhongtianWang/quilt,LuiseV/quilt,stevenlin598/quilt,ejj/quilt-dev,stevenlin598/quilt,tejasmanohar/quilt,stevenlin598/quilt,mmussomele/quilt,LuiseV/quilt,tejasmanohar/quilt,ejj/quilt-dev,stevenlin598/quilt,secant/quilt,kklin/quilt,kklin/kelda,secant/quilt,LuiseV/quilt