Documentation Changes

More proposed documentation updates.

Acceptable Formulae:

* Adds Perl to the list of stuff we offer Dupes of in the Core.
* Notes that OS X’s OpenSSL is usually horribly outdated as well as depreciated.
* Removes the incorrect space between font and forge.

Common Issues:

* We said three issues, we listed four. Oops.

External Commands:

* The cache is usually at /Library rather than ~/Library, and the rest of the documentation says /Library, so this makes the referencing consistent.

FAQ:

* Adds a tiny section on pinning formulae.

How-to-use-keg-only-outside-of-brew:
* A new piece of documentation detailing how to deal with using keg_only formula outside of Brew itself. We’ve had a lot of questions and issues about this recently, and the solutions aren’t as easy and explicit to find elsewhere, so detailing it here may help reduce some of the questions we’ve seen recently.
* I possibly whinged too much in the second section. I’m open to criticism and being called whiny.
* Details flags, prepending the $PATH, and dealing with pkg-config.

Interesting-Taps-And-Branches:
* Notes gaming-emulation software belongs in Homebrew/Games as well.
* nolith/Embedded hasn’t been touched for 28 months. I’ve cut it.
* anarchivist/forensics hasn’t been touched for 35 months. I’ve cut it.
* codebutler’s GTK+ experiment seems to have been terminated after one commit. I’ve cut it.
* paxam/linux hasn’t been touched for 34 months. I’ve cut it.
* rmyers/homebrew hasn’t been touched in 42 months. I’ve cut it.
* nddrylliog/winbrew has moved, I’ve changed the URL to the new one.

Winbrew.md:
* Removed. It’s referenced in the prior file, and doesn’t really need
its own.
Might want to keep it as `keg-only` rather than `keg_only`