pulseaudio: upgrade to 6.0

pulseaudio: upgrade to 6.0

Changes:
- BlueZ 5 native HSP (headset) support;
- BlueZ 5 HFP (hands-free) profile support via oFono;
- systemd socket activation support;
- Better support for multichannel and 2.1 profiles;
- Remap optimisations;
- Many minor improvements, bug fixes, and i18n updates.

- Switched to ${BP} variable.
- Patch 0001-configure.ac-Check-only-for-libsystemd-not-libsystem.patch
removed, no longer necessary.
- Patch CVE-2014-3970.patch included upstrem, removed.
- Slightly changed copyright notice, only a clarification.

libsamplerate based resamplers are now deprecated,
because they offer no particular advantage over speex.
Dependency to libsamplerate0 dropped.

[ RB: disable systemd until systemd.bbclass can handle user units ]

Signed-off-by: Cristian Iorga <cristian.iorga@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>