Prerelease 4.0.0-dev.0

[abitofevrything]

Description

Prerelease 4.0.0-dev.0

Checklist:

• [x] Ran dart analyze .
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works

[abitofevrything]

Will reopen when ready for stable release.