Merge pull request #237 from jclehner/1.0-dev

Allow empty SET_PARAMETER request
rtsp: don't try and take our own player lock

This can happen during a shutdown triggered by the playing thread. Fixes
issue #233 reported by therealmuffin.
rtsp: treat pthread_t as properly opaque

We use the mutex's state to determine whether the playing_thread is
valid or not. Also now use pthread_equal, as we should. Should address
issue #236.
rtsp: send responses as single packets

Under some circumstances, RTSP responses would be split into multiple
packets. This causes Airfoil to barf, as it interprets the end of the
packet as the end of the response. Since TCP_CORK is not portable, this
fix buffers the packet on the stack before using a single write.
This fixes issue #213.
README: add debian package suggestions
add support for openbsd sndio sound daemon
typo
fix shell script
Make a few fixes debian init script.

Add avahi as a start dependency, fix the provide line.
Also add a note about updating the logrotate file if non-standard
log and error files are used.
Merge OpenBSD audio driver
Return a nonzero value on error