Remove warnings from liblwgeom

These are mostly unused variables

git-svn-id: http://svn.osgeo.org/postgis/trunk@11511 b70326c6-7e19-0410-871a-916f4a2858ee
More unused variables and functions warnings cleaned

git-svn-id: http://svn.osgeo.org/postgis/trunk@11512 b70326c6-7e19-0410-871a-916f4a2858ee