When dealing with several namespaces there might be classes with the same name
(especially Global which is autogenerated in g-i based bindings). On generation
the file would be overriden by the last occurence in the xml. To encounter
this every namespace has it's own directory now. This also improves structure
a lot when dealing with big libraries.
Also do the necessary adaption for the build and the csproj files.
The only autogenerated AssemblyInfo files are in cairo and in
gtk-sharp's root, not inside other libraries like atk, glib, etc.
Removing them will make MonoDevelop stop rendering a red element
underneath each project.
