Demonstrate the Set-like nature of Options collections

Options collections are backed by Sets, and thus trying to push a new
option with a name that duplicates an existing option cannot succeed.

Later, we can exploit this behavior and remove some conditionals.
Options: ensure copies do not share the underlying collection
Add an accessor to make the intent more clear here
node 0.10.17

Closes #22064.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
node devel 0.11.6
git: Set sysconfdir during the build

Configuration files should be in /usr/local/etc (or equivalent), not in
the cellar, where git put them before.

Closes #22082.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
storm devel 0.9.0-wip21

Closes #22081.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
bash: add HEAD

Closes #22080.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
djvulibre 3.5.25.4

Closes #22076.
libcouchbase 2.1.1

Closes #22062.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
passenger: Use opt_prefix

Cleaning up places that can use `opt_prefix` instead of
`#{HOMEBREW_PREFIX}/opt/<packagename>`

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
chruby: Use opt_prefix

Cleaning up places that can use `opt_prefix` instead of
`#{HOMEBREW_PREFIX}/opt/<packagename>`

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
nexus: Use opt_prefix

Cleaning up places that can use `opt_prefix` instead of
`#{HOMEBREW_PREFIX}/opt/<packagename>`

This package had a hardcoded `/usr/local/` instead of a
Homebrew path in the .plist file.

Closes #22079.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
denominator 3.7.0

Closes #22088.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
RethinkDB 1.8.1

Closes #22085.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>