tap_migrations: support renaming to/from casks.

Add Kaby Lake to Linux hardware list

formula: don't expand unused optional dependencies

keg: installed dependencies of unknown formulae

Allow `tap_migrations` entries to have a `user/repo/formula` or
`user/repo/cask` format for migration of formulae to/from casks.

formula_installer: prevent version mismatched deps

audit: don't allow openssl & libressl dependency.

Don't drop .rb suffix for formula names

Correct location of taps (doc)

Formulae should not depend on both OpenSSL and LibreSSL (even
optionally). This is to avoid descending into madness where every
formulae that could use LibreSSL has to have option and switching logic.

Homebrew has standardised on OpenSSL and will do so everywhere that
LibreSSL is not a hard requirement.

brew deps: support --full-name in --installed, --all, and --tree modes

Because of an accidental use of `=` instead of `==`, the source formula
check would be skipped when determining if a keg depended on another one
(so only the versions would be compared).

Fixed that comparison, and updated the corresponding test.

Glad I caught that!

Previously, trying to resolve the dependencies of a keg would raise an
exception if the formulae for any of the dependencies could not be found
(e.g. if it had been moved to another tap).

This commit updates the dependency finding logic to catch these
exceptions, and fall back to comparing names and taps of formulae, which
should give the correct behaviour.

Fixes #1586.

see #1526

Fixes #1718

diagnostic: check for bad tap files.

This properly addresses Homebrew/homebrew-core#7826.

create: remove :x11 dep from new formula template

bump-formula-pr: fix removal of old mirrors

brew create: add meson support

Updated homepage 404 check to use explicit parameters and return the …

This reverts commit 862c3ba4.

Previously, old mirrors are only removed if the requested spec is
stable, and if the mirror lines only have two leading spaces. This leads
to stale mirror line(s) when the formula a stable block like

    stable do
      url "http://example.com/v1.0.tar.gz"
      mirror "http://example.net/v1.0.tar.gz"
    end

where the mirror line is lead by four spaces.

In this commit, we discard the /(^ mirror .*\n)?/ pattern, and instead
create a pattern with the exact url and flexible leading spaces for each
mirror of the requested spec.

audit: handle a nil revision map.

Deprecate 32-bit options.

Remove Xcode prerelease warnings.

These were formerly supported but as it has been a very long time since
32-bit software was necessary on macOS these have been deprecated with
a `brew audit` warning and a future `odeprecated`.

update-reset: add new command.

postinstall: don't allow writes to prefix itself.