Regenerate parser with bison 3.0.2 and flex 2.5.35

git-svn-id: http://svn.osgeo.org/postgis/trunk@12949 b70326c6-7e19-0410-871a-916f4a2858ee
Fix parser rules to run automatically if needed

git-svn-id: http://svn.osgeo.org/postgis/trunk@12950 b70326c6-7e19-0410-871a-916f4a2858ee