Create traversal methods on Directory.
Rename and generalize a bit.

Use `get`-names to be consistent with the rest of the API. Let users pass
more than one directory in at a time for convenience.
Traverse up to a parent Directory with getParent.
Traverse to parent directories too, why not!
Detect when you're at the filesystem root.
Remove unnecessary real path resolutions.
Cleaner lazy require for Directory.
added define for _WIN32_WINNT 0x0600
to ensure CancelIoEx is available
Fix Directory.contains method error on Windows

Fixes #20
Merge pull request #22 from gustavohenke/patch-1

Fix Directory.contains method error on Windows
1.2.2
Merge pull request #19 from bradgearon/master

added define for _WIN32_WINNT 0x0600
1.2.3
Ignore C4244 warnings to fix VS2012 compilation
Merge pull request #23 from nielsAD/master

Ignore C4244 warnings to fix VS2012 compilation
1.2.4
Remove an unnecessary line.
It looks like it's needed after all.
Merge pull request #18 from smashwilson/traversal

Directory Traversal
1.3.0