Check work with UNC paths

[mrmlnc]

Some info:

• https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx
• https://msdn.microsoft.com/en-us/library/gg465305.aspx

[mrmlnc]

Works fine, but only in cwd option. As expected, patterns using UNC paths are not allowed. We need to write about it in the documentation.