FCPPluginClient: Finally implement send() :)
- It is a huge nerdgasm to see that it wound up to be this symmetric :) I hope this helps to justify why I rewrote the plugin FCP stuff... 
- The incomplete parts are marked with UnsupportedOperationException throwing FIXME. They should be finished before this gets merged.
FCPPluginClient.send(): Add FIXME of simplifying the function layout