snapshot_create_as: Add "--quiesce" without unix channel negative case

Signed-off-by: Wayne Sun <gsun@redhat.com>
snapshot_create_as: Add reuse external diskonly negative case

When create diskonly snapshot with --reuse-external option fail,
the domain xml should remain not updated.

Signed-off-by: Wayne Sun <gsun@redhat.com>
snapshot_create_as: Add external memory snapshot compressing cases

Add test cases of config "snapshot_image_format" in qemu.conf before
do external system checkpoint snapshot.

Signed-off-by: Wayne Sun <gsun@redhat.com>
snapshot_create_as: Add test case for bug 872292

The "savevm command not found" log should not be found in libvirtd
log file after done snapshot, update test to cover this.

Signed-off-by: Wayne Sun <gsun@redhat.com>
Delete the sync step after libvirtd and qemu conf restore

The restore function will restart libvirtd, no need to use sync after.

Signed-off-by: Wayne Sun <gsun@redhat.com>
snapshot_create_as: Replace conf sync function

As utils_config deleted the sync function, replace it with utils_libvirtd
to restart libvirtd if needed.

Signed-off-by: Wayne Sun <gsun@redhat.com>
delete guest agent remove operation as there is no need
snapshot_create_as: Update utils_conf instance with set_string usage

The set_string function is for set string value with quote mark
in conf, which with customize result to avoid raw string in config
file.

Direct use attr function to simplify useage.

Signed-off-by: Wayne Sun <gsun@redhat.com>
Merge pull request #233 from waynesun09/quiesce_without_unix_channel

snapshot_create_as: Add more test cases