+ align text placement to pixel boundary
+ align text placement to pixel boundary

git-svn-id: 5adfda8227e14e59fd47d5bd9925a30df16fed74@2222 d397654b-2ff0-0310-9e29-ba003691a0f9

craigds/mapnik2,makinacorpus/mapnik2,craigds/mapnik2,craigds/mapnik2,craigds/mapnik2,makinacorpus/mapnik2,makinacorpus/mapnik2,makinacorpus/mapnik2