Summary:
We want to stop supporting '-multiletter' options altogether in the future as
they are not standard.
For boolean switches, we used to have '-short' for true and '-nshort' for
false, but that second form is necessarily > 1 letters, which doesn't work in
this scheme. Replace these by '-s' for true and '-S' for false.
Reviewed By: jberdine
Differential Revision: D4674079
fbshipit-source-id: 95bacfe