utils_env: Add a suffix for vm in env.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
utils_env: Return uri specificed vms in get_all_vms().

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
libvirt_vm: make normalize_connect_uri return exact uri rather than None when input is default.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
libvirt_vm: Fix for vm.connect_uri when it is default.

Default is not always qemu.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
libvirt_vm: send ^] to serial_console when vm is lxc to close console.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>