audit: various tweaks

formula_installer: install deps of dep before dep

Dependencies/requirements of a dependency need to be installed/satisfied
before the dependency. The fact that @pour_failed may be false is
irrelevant to that imperative if we weren't pouring to begin with, so
this commit now checks for that case as well.

scm/git: make --homebrew=print-path use realpath.

update.sh: reset pre-stash, die if stash fails.

docs: fix a typo in plist_options?

While using `"true"` instead of `true` wouldn't break anything, it doesn't
seem to be expected, and using `"false"` instead of `false` _would_ break
things.

Allow deprecated hash syntax in Cask headers

bottles: translate foo@1.2 to fooAT1.2

Add `--full-name` option to `brew deps`

This allows changed formulae in taps to be tested in the proper order.
See #738 for more details.

Add --full-name option to brew deps command,
which displays the full name of dependencies.

formulary: handle @ formulae.

Before this change:
```
~> brew search openssl@1.1
openssl@1.1 ✔️
==> Did you mean to perform a regular expression search?
==> Surround your query with /slashes/ to search by regex.
```

brew: execute update before tap

This seems generally like a good idea given that we're making syntax changes to
formulae & are going to keep doing so for a little while yet. Taps may have moved
over to that syntax, which then causes tap failures if brew isn't up-to-date.

Should fix situations like https://github.com/Homebrew/homebrew-php/issues/3545.

Don’t use `should` syntax in rspec.

* Replaced ; with && under Update Bug in README.md.

* Updated issue template's brew update fix.

Brew-Test-Bot-For-Core-Contributors: fix broken link

Fix missing `magenta` in Tty.

Remove `exist?` check for `brew-cask-tests.rb`.

cask tty removed

Restrict TMPDIR etc. changes to install, post_install and test

See discussion in Homebrew/brew#800.

various: update CI links.