Remove macros for unordered maps/sets

[Enchufa2]

Pretty simple one. Will rebase and mark as ready for review when #1371 is merged.

Checklist

• Code compiles correctly
• R CMD check still passes all tests
• Preferably, new tests were added which fail without the change
• Document the changes by file in ChangeLog

[Enchufa2]

Rebased.

[eddelbuettel]

Rev dep now running with tag 1.0.14.11.

[eddelbuettel]

Nice and clean, should not do damage but let's wait just in case.

(And let's keep in mind that I also skip a few of the more expensive ones...)

[eddelbuettel]

BTW I think you accidentally mistyped the buttons in the checklist. Hit number two but skip number three?

[Enchufa2]

I did! Fixed.

[kevinushey]

LGTM!

[eddelbuettel]

As anticipated, this too passed without event or issues, more here, so merging.