Made a no-cbits branch that removes several things that use C code and the FFI. I moved one of them out to a new haskell library, http://hackage.haskell.org/package/mountpoints. Others were replaced with other existing libraries. This will simplify git-annex's build process, and more library use is good. Planning to merge this branch in a week or two.

v6 unlocked files don't work on Windows. I had assumed that since the build was succeeding, the test suite was passing there. But, it turns out the test suite was failing and somehow not failing the build. Have now fixed several problems with v6 on Windows. Still a couple test suite problems to address.