This patch fixes a few minor problems with libpq++: remove the deprecated

This patch fixes a few minor problems with libpq++: remove the deprecated
PQExec(" ") in the wrapper around PQnotifies(), fix the Makefile for
the examples so that they will actually compile properly (with the
exception of #5, which depends on internal headers), make a minor change
to libpq++.h so that "make examples" now works on my machine, update
some documentation, fix some grammatical problems, and remove some of
the more hideous comments.

Neil Conway