Don't keep audio files open except when they are actually being read

right that moment ("hands-off reading").

Automatically rescan when anything is mounted or unmounted.

Both are intended to improve compatibility with removable storage.

diff --cc plugins/Makefile.am
index 3626991f5fbde7fa21a5b2cbf1fdf50e2dfb442b,410f5ae1cfdf83b3107dfb0466d2210ca0a2f345..76d792331da87483acdfab71c81984ebc1e06b37
--- 1/plugins/Makefile.am
--- 2/plugins/Makefile.am
+++ b/plugins/Makefile.am
@@@ -23,9 -23,7 +23,10 @@@ AM_CPPFLAGS=-I${top_srcdir}/li
  notify_la_SOURCES=notify.c
  notify_la_LDFLAGS=-module
  
 -disorder_tracklength_la_SOURCES=tracklength.c mad.c madshim.h ../lib/wav.h ../lib/wav.c ../lib/hreader.h ../lib/hreader.c
 +disorder_tracklength_la_SOURCES=tracklength.c tracklength.h   \
 +tracklength-mp3.c tracklength-ogg.c tracklength-wav.c         \
- tracklength-flac.c mad.c madshim.h ../lib/wav.h ../lib/wav.c
++tracklength-flac.c mad.c madshim.h ../lib/wav.h ../lib/wav.c  \
++../lib/hreader.h ../lib/hreader.c
  disorder_tracklength_la_LDFLAGS=-module
  disorder_tracklength_la_LIBADD=$(LIBVORBISFILE) $(LIBMAD) $(LIBFLAC) -lm