Updates for Digger

Rewrite of a few Digger functions. Still not working as well as I would
like.

Also updated to follow a few recent changes over at
http://github.com/ondras/rot.js

Added rng:getWeightedValue() for all Random Number Generators.
Takes a table where keys are ids for some object and values are weights
for likelihood of said object.
Fixes to ROT.Uniform

Every room should connect now!
Changes to rogue and dungeon

Rogue made to act more like dungeon.
added getDoors to dungeon.