MILESTONE and BUILD_NUMBER with new build system

[Henri Gomez]

>> David
>
> (Not addressed to David but in response to his informative comment)
>
> Ugh. Magic files and magic environment variables. That's very disappointing. Why are we using configure again?
>
> I really hoped that the new build-infra system would relieve us of this kind of hocus pocus. The build system should only be looking to the environment for ephemerals that have no visible effect on the resulting bits. This would include such things as build verbosity control, temp dir location, target dir, etc. (perhaps max-mem and max-cores too)
>
> Build parameters that do have an effect on the output bits really *must* be configure parameters. The sense of version.numbers also appears to be backwards. It should be defaults with configure params overriding. User provided params should not be overridden, silently or otherwise.

+1

BTW until it's fixed I hacked version.numbers :

https://github.com/hgomez/obuildfactory/blob/master/openjdk8-lambda/linux/build.sh