This cuts off server whose version is older than 7.4. But enables us to
remove large portions of code rarely used and tested (e.g. p2 copy) and
will allow us to drop the query we do at each connection to establish
the client encoding and the datestyle.
* 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.
