more abstract structure

* gets rid of ugly BAR and STATUS strings
* return NULL on warn/error in printing functions abusing ""
* build status with render_table, which pieces the status together
  without having to think about dirty hacks in each print function in
  functions.c

Much credit to @vodik for guidance in irc and by example; for instance,
repose/util.c:joinstring().
unneeded cast
silly me