This function generalises the existing print_cmdline used to output the qemu
command line to output any given command line, and exports it to other modules.
It also adds a timestamp to the old print_cmdline output for consistency with
guestfs___print_timestamped_message.
---
src/guestfs-internal.h | 1 +
src/launch.c | 48 ++++++++++++++++++++++++------------------------
2 files changed, 25 insertions(+), 24 deletions(-)