Proposed changes to NewActorAddress

[arajasek]

There are ~three~ four proposed changes to how actor addresses are generated in the VM. They are:

1. Use the origin address, not the _immediateCaller. This seems necessary to avoid address collisions (for example, in power_actor's CreateMiner method).
2. Use the pubkey address, not the ID address, which is what the spec currently says we should do.
3. Use the top level message's nonce, and not the top level sender's actor's nonce (since that has already been incremented by this point).
4. [New!] Replace internalCallSeqNum counting all internal message sends with a newActorAddressCount counter of calls to the method specifically, in the context of the originating message. The first value used is zero. (@anorth)

I think we already have broad consensus on these proposed changes.

cc @frrist

[whyrusleeping]

This SGTM, Thanks for writing this up @arajasek !

[anorth]

I have added a fourth change to the issue description:

Replace internalCallSeqNum counting all internal message sends with a newActorAddressCount counter of calls to the method specifically, in the context of the originating message