Log Message:
Update 1.12 to 1.15
-------------------
1.15 2014-06-24
 - Cope with Cwd::abs_path dying on non-existant paths on Windows

1.14 2014-05-20
 - Fix tests under MacOS, where TMPDIR is, by default, under a symlink

1.13 2014-04-22
 - Only expand ~ in paths if they are the first character
 - Implement include.path, as git 1.7.10 and above do