PluginRespirator: Use new FCPServer API registerPluginClient() / getPluginClient()
- The "UPDATE" part of the huge removed FIXME is not fixed yet, it won't work to implement it that way, which was briefly suspected by that comment already. There are other FIXMEs at the WeakReference members in FCPPluginClient which will cause this functionality to be implemented, so we can safely remove the FIXME here.
- The function call to FCPServer.registerFCPPluginClient() which is replaced by this comment is not actually a replacement: That function never existed, the call was merely an intentional breakage of compilation to enforce implementation of that function.
- The JavaDoc of getPluginClientByID() which is added by this commit references JavaDoc FredPluginFCPServer which does not exist yet. It will be shipped in the following commit.