Log Message:
Add lang/camlp5 version 5.01

Camlp5 is a preprocessor and pretty-printer for OCaml programs. It also
provides parsing and printing tools.

As a preprocessor, it allows to:
- extend the syntax of OCaml,
- redefine the whole syntax of the language.
As a pretty printer, it allows to:
- display OCaml programs in an elegant way,
- convert from one syntax to another,
- check the results of syntax extensions.
Camlp5 also provides some parsing and pretty printing tools:
- extensible grammars
- extensible printers
- stream parsers and lexers
- pretty print module
It works as a shell command and can also be used in the OCaml toplevel.