ensure there is a floor to tuneables such that they can't be set so a client misbehaves

There have been a few situations where people have either inavertently or not knowing what they're doing set various internal timings to incorrect values. We should create a floor or a ceiling for these and change them with a warning if the user attempts to misuse it.

From a recent code example:
    private static String serverList = "";
    private static long opTimeout = -1;
    private static long opQueueMaxBlockTime = -1;
    private static long obsPollInterval = -1;
    private static int obsPollMax = -1;
    private static long msReconnectThresholdTime = -1;
    private static long maxReconnectDelay = -1;
    private static boolean shouldOptimize = false;
    private static int timeoutExceptionThreshold = -1;
    private static boolean useNagleAlgorithm = false;
    private static FailureMode failureMode = FailureMode.Cancel;
    private static int ttl = 86400;
    private static int threads = 1;
    private static long msBeforeGet = 5000l;
    private static long repeat = -1;