* Merged NEWS-2.3 and NEWS-2.2: 2.0 (pre-async) still makes sense in case
someone has horrible problems with the new code but 2.3 will just
substitute 2.2 so having a separated NEWS file doesn't make sense.
* Moved authors and contributors to AUHTORS file.
* README now has pointers to web site and bug tracker.
* Updated MonoDevelop project.