- Stripped portions of `myocamlbuild{,_config}.ml' that seem useless
when `-use-ocamlfind' is passed to ocamlbuild.
- Added some code in `myocamlbuild_config.ml' to be able to generate
documentation by merging interface and implementation files.
On some systems, the targets "all" and "install" must be
made with different rights. Then "all" cannot be a dependendy of
"install", especially since ocamlbuild try to read/modify some
files even if there is no compilation to perform.