Remove hard dependency on camlp4

[whitequark]

camlp4 was separated from OCaml in 4.02 and is being phased out. It would be great if Camomile did not have a hard dependency on camlp4. The only part of it that depends on camlp4 is tools/camomilelocaledef.ml, and it is used for the parser syntax.

I think a viable solution is shipping already preprocessed source, e.g. just by doing:

mv tools/camomilelocaledef.ml tools/camomilelocaledef.pp.ml
camlp4o -printers o tools/camomilelocaledef.pp.ml >tools/camomilelocaledef.ml

It is not even much less readable than with camlp4 syntax.