wxWidgets 2.7 now required

["Dave Page" <dpage(at)vale-housing(dot)co(dot)uk>]

Per recent discussion, SVN Trunk of pgAdmin now requires wxWidgets 2.7
or above. Anyone building pgAdmin must therefore upgrade. I've attached
a simple script that I use to build and install all variants of
debug/release vs. dynamic/static on *nix platforms for convenience.

The plus side is that we now now longer need a custom wxAUI package :-)

Regards, Dave.