Implement split packages and wheel building

[msarahan]

closes #1338

supersedes #1410

[hainm]

fantastic. thanks.

[hmaarrfk]

Is there documentation about how to do this well?

The documentation on conda.io only gives examples of really easy package that probably don't benefit from split packages.

I'm trying to use this to split sqlite conda-forge/sqlite-feedstock#31 but I don'tl ike the fact that now we have to specify each file in the files section.

Without a split package, conda-build would automagically find the files that were installed.

Are there better ways to do it?

I kinda wish there was a way for me to say: files 1 and 2 go in this sub package, everything else go in this.

[github-actions]

Hi there, thank you for your contribution!

This pull request has been automatically locked because it has not had recent activity after being closed.

Please open a new issue or pull request if needed.

Thanks!