Fix Language::Java::java_home_cmd for Linux

os/mac/diagnostic: output non-default Xcode prefix.

Bump html-proofer from 3.9.2 to 3.9.3 in /docs

/usr/libexec/java_home is specific to macOS.
Language::Java::java_home_cmd is not implemented on Linux and raises
NotImplementedError.

Add private Language::Java::java_home_shell and use it instead of java_home_cmd.
Add public Language::Java::java_home for use by formulae.

Use Homebrew-controlled domain for Cask dummy URLs

Bumps [html-proofer](https://github.com/gjtorikian/html-proofer) from 3.9.2 to 3.9.3.
- [Release notes](https://github.com/gjtorikian/html-proofer/releases)
- [Commits](https://github.com/gjtorikian/html-proofer/compare/v3.9.2...v3.9.3

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

In a number of Cask specs, the value of the `homepage` stanza is currently set
to https://example.com. As of 2018-11-28, the TLS certificate served by
example.com seems to be expired, possibly due to an oversight on ICANN’s side.

While the certificate is certainly going to be renewed soon, it would be
desirable for Homebrew’s test result to be less dependent on ICANN’s actions.
This commit changes the homepages of all test Casks to http://brew.sh, whose
domain and TLS certificate are both controlled by Homebrew.

This should help people find it when this is a fatal error (and they
don't look at `brew config`).

Bump faraday from 0.15.3 to 0.15.4 in /docs

Bumps [faraday](https://github.com/lostisland/faraday) from 0.15.3 to 0.15.4.
- [Release notes](https://github.com/lostisland/faraday/releases)
- [Changelog](https://github.com/lostisland/faraday/blob/master/CHANGELOG.md)
- [Commits](https://github.com/lostisland/faraday/compare/v0.15.3...v0.15.4

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

audit: Disable "Don't use OS.mac?" for Linuxbrew

Tweak HOMEBREW_UPDATE_TO_TAG

reinstall: add build-from-source switch.

Fixes #5431.

list: Add help text

Cask: complete Git-Jiro's HTTPS audit check

postinstall: Use CLI::Parser to parse args

CurlDownloadStrategy: handle Location header indicating the current directory

If a response contains a Location header starting with `./`, substitute just final component of the URL path with the given filename.

Deduplicate RuboCop config.

pin: Use CLI::Parser to parse args

JavaRequirement: fix version parsing to handle Java 9 and higher

DependencyCollector: Add java_dep_if_needed [Linux]

docs: update instructions for OS X < 10.9

Simplify usage instructions for the new feature suggestion GitHub issue template

Bump github-pages from 192 to 193 in /docs

Older systems will install Homebrew via git://, but can switch to https:// if a newer curl is installed.

Bumps [github-pages](https://github.com/github/pages-gem) from 192 to 193.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](https://github.com/github/pages-gem/compare/v192...v193

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

docs: bottle is a valid formula specifier, too

Bump codecov from 0.1.13 to 0.1.14 in /Library/Homebrew/test