[postgis-devel] autoconf

[strk at refractions.net]

I've made some improvements in the autoconf script,
including support for libjts (more later on this)

Any configure runner please try newer version, being
aware that --with-geos now takes the full path
to geos-config instead of a directory.

Also, note that environmental variables are no more read
and that there is an attempt at guessing proj2 installation
directory.

--strk;