Added ClientConfig to hold configuration values
Updated client to create a ClientConfig
Made VM stack size configurable; use config

Made the client pull info from the config object rather than reading
from the raw JSON.
Added basic "in tunnel" checking

This helps fix Issue #3 by checking the tiles above your bounding box
during sliding.
Merge pull request #27 from zackthehuman/master

Fixing Issue #3, adding client config object