As unfortunate as it is to remove such useful debugging messages, it's
necessary to fix a potential deadlock with signal handling.  A bunch of
functions the debug functions call aren't safe to call from a signal
handler.  There are some alternate solutions, but they're neither pretty
nor simple.  So just remove them entirely for now.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6828 09075e82-0dd4-0310-85a5-a0d7c8717e4f