Path normalization doesn't match standard C#'s functionality

[LatteAno]

In the following unit-test, both normal C# methods are consistent with each other, while MockFileSystem's doesn'tL

[TestMethod]
public void TestPathNormalization() {
	var mockFs = new MockFileSystem(new Dictionary<string, MockFileData>());
	var vectors = new [] {
		new {input = @"c:\top\..\most\file", expected = @"c:\most\file"},
		new {input = @"c:\top\..\most\..\dir\file", expected = @"c:\dir\file"},
		new {input = @"\file", expected = @"c:\file"}, // (assuming you're running on c:)
		new {input = @"c:\top\../..\most\file", expected = @"c:\most\file"},
	};
	foreach (var vector in vectors) {
		var path = Path.GetFullPath(vector.input);
		var fileInfo = new FileInfo(vector.input).FullName;
		var mock = mockFs.FileInfo.FromFileName(vector.input).FullName;

		Assert.AreEqual(vector.expected, path, true);
		Assert.AreEqual(vector.expected, fileInfo, true);
		Assert.AreEqual(vector.expected, mock, true);
	}
}