To work around ronn's [issue with nested
lists](https://github.com/rtomayko/ronn/issues/35), treat each item as
a separate paragraph with alternate list markers.

If the formula's tap isn't tapped yet when running `brew pull`, a false
positive occurs for the nonstandard bump subject check, and a bogus
warning is printed, which claims the bump subject should refer to the
old version not the new version.

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.

Also, flag those that we never want to be in a manpage.

`test-bot --ci-testing` supports a `--tap` option for non-core taps, so
`brew pull` should too when pulling Homebrew Testing jobs.

Substitue each Version.new and HeadVersion.new with Version.create
to unify Version and HeadVersion instantiation among core code.

Note that this does not relate to Mac::OS::Version class.

Closes #377.

Signed-off-by: Baptiste Fontaine <b@ptistefontaine.fr>

* Move GitHub API module to utils/github.rb.

* Move curl method to utils/curl.rb.

* global: use long curl arguments and an array.

This makes the code more self-documenting.

* utils/curl: support reading curl's output.

* utils/github: use curl instead of open-uri.

It has far better proxy support.

* pull: set Homebrew user agent.

* gist-logs: remove trailing whitespace.

* gist-logs: use first instead of [0].

Easier to read.

* gist-logs: use curl-based GitHub.open method.

There's no more pull requests left to pull on this repository.

This means that we do not need to read formulae or evaluate Ruby at
upload time.

I'm not completely sure this is "sane" logic but I'm leery of just reverting
Andrew's work this morning and making him rebuild that PR from scratch for one
syntax issue.

Sadly, because we run:
```
brew readall --aliases --syntax
```
On every CI job, and that flags this line previously as:
```
pull.rb:555: warning: possibly useless use of a variable in void context
```

Every single PR has "failed" since it was merged, and it's reached the point
of being a bit annoying, so let's try this.

Works around issue with GET and HEAD apparently acting differently, and
bottle downloads failing even after successful polling completion.

Fix bug originating in #132.

Do the bottle check using any platform's bottle, so `brew pull` works
on bottled formulae which don't include a bottle for the current system.

Make output more concise and informative
 * Remove expected download error messages when waiting for Bintray publishing
 * Replace patch download progress bars with patch file name
 * Silence git output about switching to and from bottle-pulling branch
 * Include formula name and patch type in some progress messages

Replace `homebrew` with `brew`, `homebrew-core`, or `legacy-homebrew`
depending on context.

Replace `homebrew` with `brew`, `homebrew-core`, or `legacy-homebrew`
depending on context.

It will pull legacy formula PR from Homebrew/homebrew
TODO: remove it when it's not longer necessary

All formulae are in taps now.