Corrected typo and fixed parent folder detection

Typo correction and fixed parent folder detection if sibling directory starts with same name

Since `cleanPath` removes all the trailing slashes (https://qt.gitorious.org/qt/qt/source/84bfbd4cb090f7f77ae3b04308726d2b8ddf4792:src/corelib/io/qdir.cpp#L2118) the check at line 138 wrongly assumed that

`D:\Test` is a parent folder of `D:\TestFoo`.

![bug](https://f.cloud.github.com/assets/251973/1750571/921d685a-659d-11e3-8e5f-c5cca90367e3.png)