Port to pandas

[goodboy]

This revamps the entire measurement collection app sub-system to instead rely on pandas!

A variety of new features are added here including, but not limited to:

• more sophisticated app management over a slave cluster
• support for multiple apps run in parallel
• a new set of call blocking apps
• per app data sets/frames
• bug fixes to the core event processing logic

I still need to add docs which should come before merge.