fixed nullpointer in serialization of broadcast packets in switch/access point; reworked a couple of textures
Merge branch 'master' of github.com:MightyPirates/OpenComputers into MC1.7

Conflicts:
	src/main/scala/li/cil/oc/client/Textures.scala
	src/main/scala/li/cil/oc/client/renderer/tileentity/PowerDistributorRenderer.scala
	src/main/scala/li/cil/oc/common/block/Case.scala
	src/main/scala/li/cil/oc/common/block/Charger.scala
	src/main/scala/li/cil/oc/common/block/PowerDistributor.scala