When launching a QEMU guest the binary is probed to discover
the list of supported CPU names. Remove this probing with a
simple lookup of CPU models in the qemuCapsPtr object. This
avoids another invocation of the QEMU binary during the
startup path.

As a nice benefit we can now remove all the nasty hacks from
the test suite which were done to avoid having to exec QEMU
on the test system. The building of the -cpu command line
can just rely on data we pre-populate in qemuCapsPtr.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

QEMU supports a bunch of CPUID features that are tied to the kvm CPUID
nodes rather than the processor's.  They are "kvmclock",
"kvm_nopiodelay", "kvm_mmu", "kvm_asyncpf".  These are not known to
libvirt and their CPUID leaf might move if (for example) the Hyper-V
extensions are enabled. Hence their handling would anyway require some
special-casing.

However, among these the most useful is kvmclock; an additional
"property" of this feature is that a <timer> element is a better model
than a CPUID feature.  Although, creating part of the -cpu command-line
from something other than the <cpu> XML element introduces some
ugliness.
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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.