set bot.players[player].entity to null when player is far away

closes #96
add link to mineflayer-radar project
update README
Added the block as a second argument to blockUpdate

closes #99
add vogonistic's repl example gist to readme
Updated blockUpdated signature to pass (oldBlock, newBlock)
Merge pull request #103 from vogonistic/issue-99

Added the block as a second argument to blockUpdate
block.pos renamed to block.position

sorry I'll try to avoid this in the future. I just wanted this to be
consistent with entity.position
Ensured lookAt takes entity.height into account

Without it, the bot will always look 1.62 too high.

Verification bot here: https://gist.github.com/4637048
Merge pull request #104 from vogonistic/patch-1

Ensured lookAt takes entity.height into account
Fixed position calculation for multi block updates

Finally figured out why my bot sometimes saw that the block broke and sometimes not. 
Merge pull request #105 from vogonistic/patch-2

Fixed position calculation for multi block updates
fix blocks and recipes enum
refactor inventory clicking
Merge branch 'master' into crafting

Conflicts:
	lib/plugins/inventory.js