mpd/TODO

1) non-blocking (for other clients) update
	j) when reading new directory db, we should block some signals when 
		manipulating the directorydb, so we don't receive a signal to 
		quit in the middle of an update
	k) when bg-update, have parent print out new old stuff to log on 
		reading db, not the child
	l) IMPORTANT: look over new command list shiznit and make it much 
		cleaner, please! (in particular, move buffer2array code from 
		interface.c to command.c, and have command stuff 
		do buffer2array)
	m) MOST IMPORTANT: update needs to deal better with directories/files
		that don't exist in the db, but do exit in the fs (i.e.
		calling updated on a newly created file).

2) rewrite interface stuff, specifically command list handling etc so its less of a hack and deals with the above update stuff better

3) crosslink "list" stuff, for example, artists are crosslinked to alubms and vice versa, this way you can do list album artists or list artist albums, this will make life easier when we add genre and other metadata

4) thourougly rewrite and check signal blocking and unblocking

5) add a --update-only, like --only-create-db, only just for updating

6) use mackstann's idea of "polling" for signals instead of handling them right away, i .e. set some variables and in the sigHandler, then deal with it in select(), while loop