ENH: Update cygpath recodes to work with all installs
ENH: Update cygpath recodes to work with all installs

People can change the `/cygdrive` prefix for mounting Windows drives; `/` and `/mnt` are both popular.  `/proc/cygdrive` is always going to have the drive letters under it.
gitpython-developers/gitpython,gitpython-developers/GitPython,gitpython-developers/GitPython,gitpython-developers/gitpython