don't sio_start if we're not stopped

don't POLLIN, we only care about POLLOUT

don't change params if they're the same avoids a sio_stop in the common case of switching from song that needs similar params (such as tracks in the same album.)

inline player_init

switch to a non-blocking usage of sndio

s/player_setrate/player_setup when the function was renamed, the error messages weren't.

use a strictier pledge for `amused add' now that we're using canonpath instead of realpath(3), we can drop the rpath pledge promise.

use canonpath instead of realpath(3) so we get the same behaviour with `add' and `load'

use canonpath (from kern_pledge.c) instead of home grow "equivalent"

drop unnecessary temp variable in main_restart_track

fmt; fold long lines

use getprogname(3) instead of __progname might help with portability, see for e.g. GitHub issue #1

avoid unnecessary initialization we're just gonna memcpy all over path again a couple of lines before; a smart compiler will probably ignore the initialization anyway.

free the imsg in player after handling, plugs a memory leak

inline player_enqueue