entity / character core movement enhancements for #63
improved type system docs
destructables check against non colliding characters
layer remove reworked to fix #66
getEntitiesBy* can now search by distance and entity distance finding handles points
creature, character, and ability enhancements
small change in entity movement handling for #63
Merge pull request #67 from collinhover/dev

Creature, character, and ability enhancements + a few critical bugfixes.