GDAL & Postgres update

Fixed a problem with the Postgres installer where it would not initialize the data cluster. If you have installed Postgres 8.3.1 and it is running, there is no need to install this update.

Fixed a couple GDAL installer problems that all boiled down to Javascript errors due to bugs in the Apple installer. If you have successfully installed GDAL 1.5.1-3, there is no need to install this update.