Added in statistics beans and a whole bunch of code to capture said statistics.
Standardised on using "key" as the variable name when talking to Couhcbase, instead of a mixture of "key" and "id".
Refactored the bean code, pushing it all down into the Client where it belongs. Also used the flag now available on BeanManager from jmx-bean-management to control whether the beans code is activated or not.
Merge branch 'feature/mxbeans' into develop
Added basic read/write integration test.