Disable event logging by default

EventLogging has performance penalty. For a simple speed of light topology with a single instances of a spout and a bolt, disabling event logging delivers a 7% to 9% perf improvement (with acker count =1)

Event logging can be enabled when there is need to do debug, but turned off by default.

*Update:* with acker=0 the observed impact was much higher... *25%* faster when event loggers = 0