Fusion Reactor Fix and Packet Spam Fix

Howdy!

The first change in this pull request is for the crazy packet spam we have been experiencing. Rather than packets being sent to all players in a given dimension which can get our of hand very quickly with multiple machines has been changed. Now packets for the machines will only be sent to players within a 20 block radius (changeable in config of course) in a given dimension. What this means is people need to be close to the machines (or using them) to actually receive update information.

The only oddity this might introduce is a player standing just outside the 20 block radius would not see the machines animate but moving into this radius he would then get the update packets and it would start animating for them also.

Second change is for the crashlog we saw with fusion reactor this morning from Cozza38. This was the stacktrace for it: http://pastebin.com/wkW3ydEA

The problem was when items were attempted to be extracted or inserted into multi-block structure. To prevent this stacktrace from happening I have disabled the ability for this to happen. You can still interact with the machine like normal but you cannot automatically insert things or extract them anymore, it must be done by the player.