brewkit.rb changes ENV destructively, so lets not do that everytime a formula
is required. Now it's possible for other tools to require a formula
description without worrying about side-effects.
Since "libexec" folders under the Cellar are already private per
formula, there's no reason to create an additional folder underneath
for namespacing.
Removed the extra folder level from these formulas.
Max Howell
Adam Vandenberg