[C++] MessageQueue tracks queue size in bytes
[C++] MessageQueue tracks queue size in bytes

* Added counter for queue size in bytes

* Added log output for adding/removal of entries with detailed
  info about number of messages / bytes left in queue

Change-Id: I974f36ab178f3adc18cda5013bc668a5b46d87c5

bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr