New variable server_version_num

Today on IRC David Fetter and some others were discussing version
numbers and we realized that although libpq now provides the version of
Postgres as a number, this is still a wheel that is being reinvented by
apps many times over, as it is not available any other way. Hence, a
small patch to provide a new variable "server_version_num", which is
almost the same as "server_version" but uses the handy PG_VERSION_NUM
which allows apps to do things like if ($version >= 80200) without
having to parse apart the value of server_version themselves.

--
Greg Sabino Mullane greg@turnstep.com
End Point Corporation http://www.endpoint.com/
PGP Key: 0x14964AC8 200607292113
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8