Add ARGV.git?
Make git an installer mode
Make quieter an installer mode
Revert "Revert "FormulaInstaller: make mode reader methods private""

This reverts commit c622f27e525de4a9cc9a209a6cc0e26be60b5919.
Update watchman to 3.0.0

Remove caveats section; it has not applied since watchman switched to
using fsevents.

(I am one of the watchman authors)
watchman: add 3.0.0 bottle.