Use BSD tar's libarchive LZMA support if available

Rename tap-readme command to tap-new.

Avoid using an unnecessary `xz` dependency when it's not needed.

Write the README but also a `.travis.yml` file (and in future perhaps a
`Jenkinsfile`).

formula_installer: Remove obsolete hard dependency on cctools.

README.md: fix URL for jawshooah

Haggins -> Hagins

All things must come to an end eventually.

brew doctor: warn about SSL_CERT_FILE (#1284)

Multiple issues have been filed about this environment variable, hence
give a warning. #932 might make this unnecessary when merged, but
hopefully this warning can be merged quickly.

New-Maintainer-Checklist: update.

Further terminology in docs + link on README

Addressing a few spots where I looked for terminology and did not find what I was looking for. Input based on a recent [podcast with Mike](https://changelog.com/podcast/223)

Update to the latest status quo.

Fix warning for HOMEBREW_REPOSITORY at /usr/local

ruby-macho now performs all relocations in Homebrew.

Additionally, delete the defunct CctoolsRequirement.

keg_relocate: fix for multiline /usr/bin/file output

Deprecate apr requirement.

It's not used on enough configurations now that there's little point in
keeping it around. See e.g. `:autoconf` for prior art.

keg_relocate: relocate text_executable? files.

apr_requirement: use Homebrew's Apr for Sierra

This was omitted from #1258, incorrectly fixed in #1267, reverted in
 #1268 and re-applied in this commit.

Revert "keg_relocate: left out text_executable? check in #1258"