The compose_fade has three public exports:
set_focused_recipient
unfade_messages
update_faded_messages
All code was pulled directly from compose.js, except for the
one-line setter of set_focused_recipient. The focused_recipients
variable that used to be in compose.js was moved to compose_fade.js,
hence the need for the setter.
(imported from commit 462ca5d0d0bd58612d0197f3734a8c78de8c6d30)
Steve Howell