ABI history

[heifner]

If blocks/transactions are retrieved from history plugin or chain plugin they are prettified using the current ABI. If this ABI has been modified since the transaction/block was created then the action data cannot be deserialized correctly.

Need to store revisions of ABI used so that historical block/transactions can be deserialized correctly.

First identified in #544

[ellipticasec]

This demonstrates why I think the fact that we cannot be certain of version of the code that will run when calling an action is troubling to me.

I wish I could specify the expected hash of the code I'm about to call and it would abort if it's not the same...