docsynch-core library now available in .NET

I managed to compile the docynch-core library in .NET. Some modifications were necessary along with a custom sax-for-dotnet assembly to parse xml files in SAX manner with .NET.

There are now three packages for the docsynch-core library, one for JAVA (essentially a jar file), one for .NET (two assembly-dlls) and one for the source distribution (includes java and dotnet source, they mainly use the same files).