convert code to compatible w/Java 6; fixes for new Bukkit API
fixes
tweak monster light spawn

- configurable light level allows more frequent (even daylight) mob spawns
- tweakable percentage to throttle back in a more fine grained way
update pom - latest bukkit + me
PR feedback
pom tweaks
downrev bukkit API version to fix upstream repo issue
bump version number
PR feedback; refactor to single EntityHelper method
Merge pull request #23 from bluekelp/bluekelp-more-mob-tweaks

Bluekelp more mob tweaks