[ELGIS] RFC: Move PostGIS client applications into separate package

[Mathieu Baudier]

> Attached is a patch, which separates the PostGIS client applications,
> shp2pgsql and pgsql2shp and shp2pgsql-gtk, from the PostGIS server side.
> In our scenanrio, the machine, which imports/exports data is not always the
> machine hosting the database server.

Shouldn't we have 'postgis' Requires 'postgis-client'?
People may expect to find the utilities if they installed postgis on a server.