Improve logging

[kpdecker]

Things that might be runtime concerns:

• Emits that still have pending operations
• Logging what pending operations are causing the page to remain open at any given time. Include stack trace that created the pending operation as well.
• Maximum pending stack size at any point
• Ajax calls and timing
• Misses for various caches
• cache errors

Need to figure out both how to do this in the most performant manner as well as decide if/how we want to integrate with frameworks like hapi.

[kpdecker]

One possibility here is that we can create a report object similar to the report parameter used by Catbox Policy objects to include this additional metadata.

[kpdecker]

Released in 0.11.0