Multiple bugfixes

* Fixed compilation on VC2013
* Fixed redstone self powering - still one more scenario to go
+ Redstone wire now powers block beneath
* Improved code: functionized stuff, and reduced unneeded GetBlockMetas;
also utilised direct chunk access, as recommended by xoft
+ Added torches powering blocks above it
* Fixed repeaters getting power when they shouldn't
- Stopped wires getting power from another wire through a block, which
could lead to wire-powering loops (vanilla behaviour)
+ Added lever location checking
* Fixed button location checking
* Fixed button pressing/unpressing
* Fixed repeaters not updating
* Fixed repeaters not receiving power from a redstone wire
+ Implemented biome based random spawn point generation