Merge pull request #137 from DanielFabian/master

Add "// <auto-generated/>" header to the c# assembly info file, so that…
Added test for replacing XML value specified by a namespace'd node. Added null comparison in XmlPokeNS
Added a test for XmlPokeNS. Both tests are green, so we have a valid example how to patch the app.manifest when running FAKE.
Fix: Do not append a newline if using ReplaceInFile:

Use File.WriteAllText in ReplaceFile instead of WriteStringToFile false.
WriteStringToFile false has the behaviour, that in every case a newline is appended, because the text is passed as a singleton list of lines and WriteToFile appends each line using a StreamWriter.WriteLine thus resulting in the last line introducing an additional newline.