RELEASE CANDIDATE: v3.0.0 rc5 (final, for really real this time?)

[Warren Young]

The biggest change in this one is the Null<T> stuff:

     http://tangentsoft.net/mysql++/test/mysql++-3.0.0-rc5.tar.gz

or for the RPM folk:

     http://tangentsoft.net/mysql++/test/mysql++-3.0.0-rc5.src.rpm

Beta docs (check out the user manual's breakages chapter!):

     http://tangentsoft.net/mysql++/test/doc/userman/
     http://tangentsoft.net/mysql++/test/doc/refman/