For ENG-6333, first version of latency watchdog.
For ENG-6333, use java thread instead of voltDB scheduleWork thread,
insert latency inspection points in network threads and ExecutionEngine
thread.
For ENG-6333, 2nd version of latency watchdog.
For ENG-6333, add logging rate limiter in latency watchdog.
For ENG-6333, change latency spike monitor points to see if latency
watchdog works.
For ENG-6333, add more latency spike inspection points.
For ENG-6333, replace System.out.println with VoltLogger.
For ENG-6333, run() method of latency watchdog should be sychronized.
For ENG-6333, use ConcurrentHashMap instead of HashMap.
For ENG-6333, use linked hash map to record timestamp per thread.
For ENG-6333, remove debug code.
For ENG-6333, add license header and method description.
For ENG-6333, use ConcurrentHashMap to record timestamp per thread,
start watchdog thread by reading system property.
For ENG-6333, remove WatchdogTimestamp, use AtomicLong to record
timestamp, lazySet timestamp if there is old timestamp value. Add
latency spike watch points.
For ENG-6350, add support for rate limiting snapshots
ENG-6312 tweak test to avoid HSQL wrong answer scenario
For ENG-6333, minor refactor to remove isEnabled method, rely on inlining instead, use thread local to get at the value, log using HOST logger at info level
delete trailing whites in SQLGenerator.py
Merge pull request #1378 from VoltDB/ENG-6333-latency-logging

Eng 6333 latency logging
Merge branch 'master' into ENG-6350