Many improvements to the visulization stack
1) draw() can now send data to drawdaemon running in another machine launched using monitor
through scheduler. FIFO is replaced by TCP socket.
2) draw() now only send data for current tab in drawdaemon or first time data.
3) drawdaemon can pause update of image. Displays FPS.
4) multiple live drawdaemon can be served by maos. Can be individually controlled.
5) maos no longer talks to scheduler for drawdaemon. It uses draw_helper(). Removed code in
scheduler_server/client about drawdaemon
6) monitor can now launch drawdaemon to show progress of a maos run.