Update macros/ruby.m4 for ruby 1.9.x

Used RbConfig instead of obsolete and deprecated Config.
Updated SWIG generated files.

Patch by Kashif Rasul <kashif.rasul@gmail.com>

git-svn-id: http://svn.osgeo.org/geos/trunk@3772 5242fede-7e19-0410-aef8-94bd7d2200fb