Moved default buffer size

The default buffer size is now set it the dispatcher rather than the
buffer. this allows different defaults for different types of dispatcher
and makes the value available to report in the log statement during
dispatcher creation.
Updated emonhub.conf

The configuration file has been left behind during developments to
default settings etc. This commit just removes some stuff that is no
longer mandatory, It also shows how minimal it could be.
Merge pull request #56 from otherWIP/development

Updated emonhub.conf & default bufferSize