(MCO-346) - Fix Data plugin and Agent load ordering

In 2.5.0 the rewrite of the runnner class the load ordering of Data
plugins and Agents were changed around. This causes Data plugins that
depend on agents like for example activate_when{PluginManager['service_agent']}

This commit restores the order.
Merge pull request #197 from ploubser/bug/stable/MCO-346

(MCO-346) - Fix Data plugin and Agent load ordering