Update brew-cask.1.md to include _stanza internal command

Revert "formula_cellar_checks: check for prefix/etc."

pull: better handle missing bottles.

If we make a PR in which we're building many formulae (e.g.
https://github.com/Homebrew/homebrew-core/pull/9249) then we may want
to pull those that built and publish their bottles and discard those
that did not. Instead of saying bottles will be published when they
won't and then blowing up just avoid publishing them and print a warning
instead.

caveats: add newline after keg only reason.

audit: improve homepage audit reliability.

Split two headers so that both render

The "Messaging" heading was failing to be rendered due to a missing newline between it and "Convenience Tools".

update-reset: checkout with --force.

formula_cellar_checks: check for prefix/etc.

Otherwise it won't overwrite unmerged changes.

Try first with an (exact, actual) browser user agent from Safari and
then try again with the default Homebrew `curl` user agent.

This directory indicates that configuration files have been installed
into the wrong location.

Cleanup Cask test directory.

Update outdated link

Move Cask fixtures to `test/support/fixtures`.

language_module_requirement: use arrays.

This is cleaner, easier to understand how the arguments are split and
fixes #1799.

man: remove an unnecessary `else`

Add docs on persisting settings across upgrades

caveats: tweak keg-only messaging.

Slim down the existing text and make it more obvious what's happening.
Note specifically how to add it to your PATH to convince people to try
that instead of `brew link --force`.

Remove some remnants of Ruby 1.8.7 support

xcode: reduce minimum CLT version.

This should be 1.0.0 to be nicer to 10.7 users.

Fixes #1893.

audit: exempt wine's deps from the universal deprecation