Allow running the plugin as a script.
Allow running the plugin as a script.

I have reorganized the plugin script to allow running the code as a
script so that it's easier to develop the code.

Signed-off-by: Warren Turkal <1c01a65c7a4125e8293dc90f61316d18ba72756a@signalfx.com>

deniszh/collectd-activemq-python,BarthV/collectd-activemq-python