pil: fix download

Closes #20818.
uses: fail fast if invalid formula names are given

Fixes #20819.
Formula.each: note why import failed

Refs #20819.
Detect Command Line Tools on Mavericks.

Closes #20774.
brew-test-bot: force fetching formulae.

References #20807.
ARGV: filter build-bottle from dependencies.

Fixes #20682.
brew-test-bot: don't install dependencies first.

Now that --build-bottle is filtered we don't need to worry about extra
installation time.
Reword uses comment
Move Formula.factory into new Formulary module
wip
wip
wip - use formula loaders
add more docs
use better var names
Don't use Object.const directly
wip
wip
wip
add raise
remove support for passing formulae to factory