[INCOMPLETE] Plugin talker sync send

This pull request adds synchronous FCP send function for plugins running in the same node.

The codepath for plugins which are NOT running in the same node is NOT implemented. Therefore this pull-request is incomplete. 
I am sending it already nevertheless because WOT master branch needs this to compile. 
As usual, Java multithreading just served it's purpose of making people shoot themselves in the feet very well: It CAN wake up even if the condition is NOT met, see the JavaDoc:
> The lock associated with this condition is atomically released and the current thread becomes disabled for thread scheduling purposes and lies dormant until one of three things happens:
> - Some other thread invokes the signal() method for this Condition and the current thread happens to be chosen as the thread to be awakened; or
> - Some other thread invokes the signalAll() method for this Condition; or
> - A "spurious wakeup" occurs."

Notice that I remember the disgust which I felt for this and I also feel like remembering searching for like half an hour for a more beautiful way to do this. There isn't. This is the right way.