Logging updates required for Base porting effort
* Remove 0.6 compatibility junk
* Ensure logging macros can be used earlier in Base
* Remove unnecessary types from core logging method defaults
* max_log -> maxlog for log limiting
* Beef up SimpleLogger a little to avoid temporary buffer async issues,
respect maxlog, and make log colorization more consistent. It can be
re-simplified again once there's a viable alternative in stdlib Logging.
* Hash entire expression for log event ids. This makes ids more likely
to be unique before deduplication, which makes them more likely to be
stable.
