Added additional power generation configuration (#1164)
 * Can now configure heat generator power from adjacent lava
 * Can now configure heat generator power from the nether
 * Wind power is now configured by specifying minimal and maximal Y levels and generation values.
    * Defaults to 60J/t at Y 24 and 480J/t at Y 255
Merge pull request #1622 from bshelden/1614-powergen-config

Added additional power generation configuration (#1164)