Convert all uses automatically, via these two commands:
git grep -l '\<exit *(1)' \
  | grep -vEf .x-sc_prohibit_magic_number_exit \
  | xargs --no-run-if-empty \
    perl -pi -e 's/\b(exit ?)\(1\)/$1(EXIT_FAILURE)/'
git grep -l '\<exit *(0)' \
  | grep -vEf .x-sc_prohibit_magic_number_exit \
  | xargs --no-run-if-empty \
  perl -pi -e 's/\b(exit ?)\(0\)/$1(EXIT_SUCCESS)/'
* .x-sc_prohibit_magic_number_exit: New file.

Edit (RWMJ): Don't change Java code.

This commit changes guestfs_launch so that it both launches
the appliance and waits until it is ready (ie. the daemon communicates
back to us).

Since we removed the pretence that we could implement a low-level
asynchronous API, the need to call launch() followed by wait_ready()
has looked a bit silly.

Now guestfs_wait_ready() is basically a no-op.  It is left in the
API for backwards compatibility.  Any calls to guestfs_wait_ready()
can be removed from client code.

* examples/hello.c [HAVE_CONFIG_H]: Include <config.h> conditionally.
* examples/to-xml.c: Likewise.

* ocaml/guestfs_c.c: Include <config.h>.
* examples/to-xml.c: Likewise.
* examples/hello.c: Likewise.