Merge branch 'mh/abspath'

* mh/abspath: t0060: split absolute path test in two to exercise some of it on Windows t0060: verify that real_path() removes extra slashes real_path(): properly handle nonexistent top-level paths t0060: verify that real_path() works correctly with absolute paths real_path(): reject the empty string t0060: verify that real_path() fails if passed the empty string absolute_path(): reject the empty string t0060: verify that absolute_path() fails if passed the empty string t0060: move tests of real_path() from t0000 to here