`brew options --installed` will now "do the right thing".
There is getting to be a small but noticeable amount of code duplication
among commands that take options like "--installed" or "--all"; it may
be worth factoring this out into a method that will return a collection
of formula objects based on the options that are passed.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
`brew options --installed` will print options for formulae that are
already installed.
ClosesHomebrew/homebrew#7565.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
