CC-5859: Airtime Analyzer: format fields before writing to db
CC-5860: Analyzer HTTP requests can hang indefinitely

* Log a backtrace when sent the USR2 signal (kill -SIGUSR2 <pid>)
* Rigged up up something to strace and restart when we see a request hanging
Merge branch 'cc-5709-airtime-analyzer' of github.com:sourcefabric/Airtime into cc-5709-airtime-analyzer
Merge branch 'cc-5709-airtime-analyzer' into cc-5709-airtime-analyzer-saas