Create doc-cmt tool

[lpw25]

Doc-ock will work with OCaml 4.02.2 when it is released. However, it will not work for people using camlp4.

There needs to be a tool based on the original docs patch for creating "enhanced" cmt files containing doc strings.

The tool would also allow support for versions 4.02.0 and 4.02.1 but, since those are essentially deprecated by 4.02.2, it is probably not worth the trouble.

[dsheets]

It appears that there is basically no support for interfaces compiled with camlp4. This prevents prose documentation generation for core, async, and mirage libraries in general. Could you detail what, exactly, this tool would do? It sounds like it may be a better user experience to modify camlp4 to help it retain documentation comments. I don't know how painful that modification would be, though.

Also, the title of this issue is a bit misleading. Maybe "support camlp4"?