move upper_case_acronyms back to style, but make the default behaviour less aggressive by default (can be unleashed via config option)
Previous discussion in the bi-weekly clippy meeting for reference: https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Meeting.202021-02-23/near/227458019
Move the `upper_case_acronyms` lint back to the style group.
Only warn on fully-capitalized names by default.
Add add a clippy-config option `upper-case-acronyms-aggressive: true/false` to enabled more aggressive linting on
all substrings that could be capitalized acronyms.
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changelog: reenable upper_case_acronyms by default but make the more aggressive linting opt-in via config option
ef41f2baf7