Fix "'input'  defined but not used" warning on building generated parser

git-svn-id: http://svn.osgeo.org/postgis/trunk@12945 b70326c6-7e19-0410-871a-916f4a2858ee
Fix grammar file to work around suspected bison 3.0.2 bug

See http://lists.osgeo.org/pipermail/postgis-devel/2014-September/024507.html

git-svn-id: http://svn.osgeo.org/postgis/trunk@12946 b70326c6-7e19-0410-871a-916f4a2858ee
Fix %name-prefix usage in gramma file

Fixes warning: deprecated directive, use ‘%name-prefix’ [-Wdeprecated]

git-svn-id: http://svn.osgeo.org/postgis/trunk@12947 b70326c6-7e19-0410-871a-916f4a2858ee