Add debugging for non started queues and queues that are filling up

[RichardHightower]

If you set these env variable or system properties,

    private final boolean checkStart = Sys.sysProp("QBIT_CHECK_START", false);
    private final int checkStartWarnEvery = Sys.sysProp("QBIT_CHECK_START_WARN_EVERY", 100);
    private final boolean checkQueueSize = Sys.sysProp("QBIT_CHECK_QUEUE_SIZE", false);
    private final int checkQueueSizeWarnIfOver = Sys.sysProp("QBIT_CHECK_QUEUE_SIZE_WARN_IF_OVER", 10);

Then QBit will check to see if a queue was started and issues warning if it was not started. You can leave this on and check every 100 times or you can check every time for debugging.

You can also instruct QBit to check for queues whose size are over a certain limit.

These setting are off by default and are mainly used during development to make sure you have setup QBit correctly.