added support for `requiredColor` and `deniedColor` as specials
changed path to tiles.png
added support for `noForward` in TMX Specials
added support for `denyDirections` in TMX specials
fixed some string vs. integer loading bugs
added `blockLink` specials support in TMX maps
file names for internal levels now start at 1
added tutorial levels 4-7
added tutorial level 8 and 9