Bug 746124 - Fix windows specific issues in FS module.

It looks like on windows there were few issues:

1. Error thrown when reading non existing directory is not `NS_ERROR_FILE_TARGET_DOES_NOT_EXIST` but `NS_ERROR_FILE_NOT_FOUND` instead.
2. On unix closing `nsIBinaryInputStream` / `nsIBinaryOutputStream` closes associated `nsIFileInputStream` / `nsIFileOutputStream`, while on windows they need to be closed manually.

With this fixes all tests pass on my virtual windows and OSX.