Add a new Getopt module to mllib, to parse command line arguments with
handlers close to the ones used with Arg, but using getopt(3) (actually
getopt_long_only) to do the real parsing. This allow us to provide
options for OCaml tools with a syntax similar to the C tools, and use
the additional features getopt offers and Arg does not.
Getopt now handles every part of the command line handling, including
the output of short & long options.
Do a single-step conversion of Common_utils and all the OCaml tools to
the syntax of Getopt.
Move a couple of utility functions from Common_utils to Getopt, since
they fit better there (and Common_utils cannot be used in Getopt, as
the former already uses the latter).
As side-change due to the conversion, extra arguments for sysprep
operation can have more keys for the same argument.
0f7bf8f714