- don't stop program execution if style uses too many different tags,
only throw MapFailedException
- remove unused code, 
- avoid some(un)boxing in frequently called routines

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@3296 25d90789-57f7-4ee0-8453-03a3dfeeeb22
simplify code, no functional change

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@3297 25d90789-57f7-4ee0-8453-03a3dfeeeb22