Complete `log` output

[mikera]

log capability is incomplete.

We still need to:

• Ensure log entries are captured sequentially within each transaction
• Copy to overall log at end of transaction
• Add log indexes

[helins]

I think last time we spoke about this the question was about how to structure the "global" log, how to index it etc.

In reality, isn't it defined by the specific needs of a given peer? A scalable solution would be simply to have a hook for that which merges the transaction-local log with whatever you want after a transaction, with a sane default hook which keeps it simple (no particular indexation or anything fancy).

[mikera]

I think the CVM log is sufficiently important that it needs to be standardised. Peer operators can of course do whatever they want, but we need a decent standard implementation with specified (and testable!) behaviour.