[WIP] v1.0.0-rc.1

[bartlomieju]

Waiting on #4933

Tentatively set versions to 1.0.0-rc.1 but I'm pretty sure we don't want that for deno_core, deno_typescript

[nayeemrmn]

Is std going 1.0 as well? We still need to go through and underscore all private modules. I feel like the release cycles should split now... std should be able to have more breaking changes, right? Also it's harder to set a versioning example for third party libs when std has this special position.

[ry]

0.42.0 (or 0.41.1 .. not sure if we made any API changes here)

[bartlomieju]

Going with v0.42.0 instead in #4986

[ry]

(We will do 1.0 rc1 in a few days - but due to the number of API changes we want to make another point release first and potentially address any issues.)