partial fix for kafka 0.8.0-beta1 compatibility.
it looks like the JMX bean structure has changed so 0.8.0-beta1 only works if JMX is disabled (and JMX disablement is respected now).
(furthermore it looks like there are errors as bean names are wrapped in an extra pair of double quotes inside jconsole.)
Merge pull request #847 from ahgittin/fix/kafka

partial fix for kafka 0.8.0-beta1 compatibility