PluginRespirator / FCPPluginClient: Move construction code to factory function
- IMHO the getPluginManager.getPluginFCPServer() code is better placed in FCPPluginClient. It's nice to have all code related to FCP server/client stuff there, makes it more self-contained.
- It doesn't make sense to move the registration code to the construction function because IMHO freshly constructed objects should be safe to be thrown away afterwards. This is good because we might temporarily create objects which are thrown away for threading reasons as seen in FCPConnectionHandler.getPluginClient()