Upgrade for current seed master

[akhilman]

I am updating the code so that I can fix the seed-rs/seed#364 .

[akhilman]

@MartinKavik I have this error message/ Everything works as expected if I delete this overlay in browser. How to fix this?

[MartinKavik]

• It looks like a popular error - Warning: Critical dependencies. webpack/webpack#196.
• I think we can ignore it - try to disable it with Warning: Critical dependencies. webpack/webpack#196 (comment).
• I can't reproduce it on my machine (at least with the current yarn.lock).

[akhilman]

What to do with generated::css_classes::C and new C! macro?

[MartinKavik]

Is compiler sad because of the name conflict?

[akhilman]

Actually compiler is totally fine with the name similarity.

[MartinKavik]

I hoped that there won't be any problems - nice.
So... I suggest to do nothing - we can decide what to do with it in the future (if ever).