This patch provides vec2map and postgis drivers rewritten:
1. they don't need GEOS library anymore, now my own code deals with WKB data
2. postgis helper classes have Convert() methods redesigned so using them there's need to do very nasty casts from const to non-const pointers. As a consequence, copy = false logic is used on Publish() calls which makes sure everything allocated by Convert() call was deleted after use.
I was working with snapshots taken 2008.09.21 and 2008.09.22