FormulaInstaller: fix "optional build-time dep" edge case

An "optional build-time dep" is unlikely, but possible, and I happen to
notice this wasn't handled correctly while digging around in the deps
code over the last few days.
latex2html 2012
latex2html: fix indents
terminal-notifier: Build from source

Patched to build without code signing because, obviously,
we don't have the developer's certificate.

Added HEAD. But please note, if built with --HEAD, you
also have to `brew test terminal-notifier --HEAD`.
terminal-notifier: Only supports 10.8

I think notification center is not availabe on 10.7 or older.

Added a caveat that without code sign, terminal-notifier
will not be able to open URLs or apps.

Fixed audit about SYMROOT.
terminal-notifier: Style bits.
selenium-server-standalone: 2.33

Closes #20242.

Signed-off-by: Samuel John <github@SamuelJohn.de>
terminal-notifier: test seems to hang on brew-test-bot
boost: don't use bottle if python brew installed.

Closes #20124.
Don't error out on unreleased OSX versions.

References #20142.
jenkins 1.517
python: Prevent potential build failure

that is caused by not calling the right (newly built)
python binary.

Fix #20245 hopefully.
mercurial: Install python bindings properly

Also allow to build with --HEAD by making brew's
download strategy aware of a brewed but unlined hg.

Adapted the caveats so that the procedure to brew
hg --HEAD is clear.

Mention how to config hgk in the caveats.
Python: Don't use named tuples to get the version

sys.version_info.major is only possible on 2.7+ or so.
Therefore, we now use [0] instead.
Extract attr_rw from Formula for reuse

Closes #20239.
lzlib 1.4

Closes #20253.
Remove postgresql and mysql audit noise

Closes #20159.
Nginx devel 1.5.1

Closes #20247.

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

Closes #20250.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
latex2html: tex is recommended

Closes #20237.