[Meta-issue] Upstreaming changes from custom fork

[jaimergp]

I've been working on a constructor fork for several months now, which implements several open issues here as well as other features. I have some time now so I will begin to upstream those changes. I will use this issue to track progress:

• conda_interface doesn't support alpha/beta/rc conda versions
  • PR: FIX: conda_interface should be able to handle alpha, beta, rc versions #496
• Improve PKG branding and signing
  • PR: Add branding features on MacOS PKGs #469
• Add signing for Windows installers
  • PR: add windows installer signing #475
• Customization of installer options (conda init, add to PATH) - only relevant for conda distributions
  • PR: add initialize_conda and register_python keys to control whether to show these options #507
• Additional files (see Include additional files in construct.yaml #465)
  • PR: add support for additional files #500
• Multi environments (see Allow for the creation of multiple environments with custom names #359)
  • PR: add support for multi_env installers #509
• Support for new menuinst
  • PR: Add cross-platform support for the new menuinst #474

[jaimergp]

Hi @conda/constructor! I hope this tag works, I think it's the first we are using it!

This team was created to help maintain constructor and related tooling and I figured I could ask for a couple reviews in the PRs mentioned in the comment above. These changes have been part of the napari fork I've been maintaining for some months, so they should work quite ok, but maybe there are rough edges in some cases.

Anyway, I would be super happy if an extra pair of eyes could give it a read and tell me what they think.

[larsoner]

These changes have been part of the napari fork I've been maintaining for some months, so they should work quite ok, but maybe there are rough edges in some cases.

@hoechenberger has also successfully used them in https://github.com/mne-tools/mne-installers for the last ~6 months so we have some evidence that things work. I'll take a look, @hoechenberger if you could look, too, that would be great!