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