Implement new method to control the player using fifo.

The player is started with an open fifo pipe for control, after which
the current playing file is detected and an entry is added to the
resume-cache file after its done playing

Since mplayer has to be started before we give it any option the fifo
pipe is used to seek to the last location instead

the advantage is that all arguments including filename are passed
directly to mplayer now.