Use cmdliner in tlapm

This slightly changes tlapm's command-line syntax:
- deprecated options are no longer accepted: `-d`, `--paranoid`,
  `--isaprove`, `--fpdir`
- options that used to take two arguments (as in `--opt A B`) can now
  take them as a single comma-separated argument (as in `--opt A,B`):
  `--toolbox`, `--nofpl`, `--erasefp`

Thanks to Damien Doligez for the backward-compatibility hack for
parsing of options that take two arguments.

Signed-off-by: Stephane Glondu <[email protected]>

src/dune

@@ -19,6 +19,7 @@
   unix
   threads
   str
+  cmdliner
   dune-site
   dune-build-info
   camlzip ; main deps.