basic system for registering file systems for lookup in a machine's rom. this allowed cleaning up the lua implementations a bit, too, since the rom is now managed by the machine itself again; fixed potential NPE when filesystems without a label implementation were created
rom isn't shared among computers anymore (i.e. shared handles); fixed swtich block not queuing cc events
Merge branch 'master' of https://github.com/MightyPirates/OpenComputers into MC1.7

Conflicts:
	src/main/scala/li/cil/oc/common/Proxy.scala