Wrap any log calls in Memcached/HotRod servers around if enabled calls

While profiling Hot Rod, I keep seeing time being spend in these:

2.3% - 25,569 ms - 140,862 inv. scala.LowPriorityImplicits.genericWrapArray (line\: 56)
...
2.2% - 24,713 ms - 140,862 inv. scala.LowPriorityImplicits.genericWrapArray (line\: 231)

These appear to come from trying to create arrays when for log messages, i.e.:
trace("Decoded header

", header)

trace method definition:
def trace(msg: => String, params: Any*) = if (log.isTraceEnabled) log.trace(msg, params.map(_.asInstanceOf[AnyRef]) : _*)

So, change all trace calls to be protected by "if (log.isTraceEnabled)" to avoid wasteful creation of arrays.