When we are starting a qemu process for an incomming migration or
snapshot reloading we should not modify the memory sizes in the domain
since we could potentially change the guest ABI that was tediously
checked before. Additionally the function now updates the initial memory
size according to the NUMA node size, which should not happen if we are
restoring state.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1252685

On my machine, a guest fails to boot if it has a sound card, but not
graphical device/display is configured, because pulseaudio fails to
initialize since it can't access $HOME.

A workaround is removing the audio device, however on ARM boards there
isn't any option to do that, so -nographic always fails.

Set QEMU_AUDIO_DRV=none if no <graphics> are configured. Unfortunately
this has massive test suite fallout.

Add a qemu.conf parameter nographics_allow_host_audio, that if enabled
will pass through QEMU_AUDIO_DRV from sysconfig (similar to
vnc_allow_host_audio)

This patch teaches testutil how to read multi-line input files with
backspace-newline line continuation markers.

The patch also breaks up all the single-line arguments test input files into
multi-line files with lines shorter than 80 characters.

We keep support for the pty based monitor so that we can re-connect
to VMs started by older versions of libvirtd.

* src/domain_conf.c: handle formatting and parsing unix monitors

* src/qemu_driver.c: add qemudOpenMonitorUnix(), remove the monitor
  pty path searching from qemudFindCharDevicePTYs(), switch
  qemudStartVMDaemon() and qemuDomainXMLToNative() to using a unix
  monitor

* tests/qemuxml2argvtest.c: switch to using a unix monitor

* tests/qemuxml2argvdata/qemuxml2argv-*.args: update test data

virExec will write out the pid of the daemonized process only. Use this
in the QEMU driver, rather than QEMU's pidfile, so we can catch errors we
might miss if the emulator bails early.