First, make sure we call finishPlaylist() before
closeMp3Directory() since the latter will free non-SONG_TYPE_URL
songs in playlist, which causes an invalid read when we try to
look for SONG_TYPE_URL songs to free in finishPlaylist.

Secondly, make sure our children have all exited before freeing
the playerData.  If we do not, slowly-delivered signals can
trigger a race condition in the signal handlers of the decode
and player processes which rely on getPlayerData.  To avoid
waitpid-ing too long (or at all), move the freePlayerData() call
farther down in main() (this won't affect anything else)
to give the OS a better chance to deliver signals and finish running
sig handlers for terminated children.

git-svn-id: https://svn.musicpd.org/mpd/trunk@4640 09075e82-0dd4-0310-85a5-a0d7c8717e4f