make bootstrap posix compliant and remove 401 and 402 version

[stopusingghpls]

Hello,
this solves #184 ,since bash is no longer required, only a posix compliant shell.

Test Doku: https://asciinema.org/a/7adgEBBcsCEZ5eNaxPSAnzipD

Also removes possibility to use these versions of ocaml: 4.01, 4.02
Since (4.03)[https://ocaml.org/releases/4.03.0] is out since: 2016-04-25
This should be fine.

[jeromemaloberti]

Thank you, but I prefer to keep 401 and 402. Can you resubmit without the removal ? Or do you prefer me to do it ?

[stopusingghpls]

Thank you, but I prefer to keep 401 and 402. Can you resubmit without the removal ? Or do you prefer me to do it ?

I am afraid this if [[ $OCAMLVER < "4.02.0" ]] is not possible in posix shell, that is why I removed the 401 and 402 in the first place. Why do you prefer to keep them, they are almost 10 years old?

[jeromemaloberti]

With opam it is easy to have multiple, potentially old versions of ocaml, so the system ocaml is not very relevant anymore. The API changed with these versions, and not all libraries/programs have been ported to newer ocaml, so I prefer to keep obuild compatible with as many version as possible.
Obuild.obuild uses configure.ml to copy the right version, it seems to me that bootstrap should call configure.ml once ocaml binary is detected. That would simplify the maintenance of bootstrap.

[stopusingghpls]

Obuild.obuild uses configure.ml to copy the right version, it seems to me that bootstrap should call configure.ml once ocaml binary is detected. That would simplify the maintenance of bootstrap.

Ok, i don't know what you mean by that. So if you know how to do it, I would prefer you to do it, the rest of the script is posix compliant.