Move casemap out of experimental; final graduation cleanups

[Manishearth]

Part of #3234

There is one leftover issue to be decided there, #3801 , btu I'm comfortable doing the moving right now and we can fix that before release if needed.

[Manishearth]

One question is: icu_casemap the feature got removed from datagen and the metacrate, since it's mandatory now. Should I still have a placeholder feature? or for experimental stuff do we consider the features themselves to be experimental

[robertbastian]

We should remove the feature, clients will need to update their code for API changes anyway.

[sffc]

#3234 (comment)

[sffc]

One question is: icu_casemap the feature got removed from datagen and the metacrate, since it's mandatory now.

I thought both datagen and the metacrate had component-specific features ?

[Manishearth]

@sffc can we please merge this without finishing the checklist? That checklist was not complete before you added more entries to it, I'm aware there's more work to be done there.

I don't think moving this component must be the last step, I'm happy to remove the "fixes ..." from the PR body but there's basically no chance 1.3 is happening without stabilizing this and we should land this somewhat churny PR at some point.

I thought both datagen and the metacrate had component-specific features ?

nope, only for experimental

this is the first time in the datagen features world we are graduating from experimental

that said, it occurs to me these features did not exist pre-1.3 anyway so this change is something that can be made without breaking anyone; next release we will need to figure out what to do about experimental components that graduate

[Manishearth]

I had some time and I've gone ahead and resolved most of the checklist items. I'd prefer to get this merged to avoid conflicts rather than blocking this on incomplete checklists, though, so if there are things still unhandled I would love to know but would prefer to not block landing on it.

[sffc]

nope, only for experimental

ok, it's not implemented yet: #3165

I think we've mentioned whether we want to do this for the metacrate but I think the consensus has been that you should use the specific crates instead of the metacrate in that situation.

I'll defer to Robert on this; the PR is large with many commits and I don't have time to give it a thorough review

[sffc]

defer to Rob on this PR. If Rob doesn't review then add me back in a few days.

[Manishearth]

autosubmit=true

[robertbastian]

There are lots of files showing as additions, I think you have components/casemap/casemap

[robertbastian]

Made some changes so autosubmit turned off