This shows a date on a message header whenever the date of that
message is different than the date of the previous message.
The previous logic was bugged and didn't display dates in headers at
date transition points.
The messages being passed to the handlebars templates were global
messages which we were adding per list details to, show name bar etc.
This causes rendering bugs when you try to rerender a message, because a
different list may have changed it. This commit moves the global message
data to a msg attribute on the message_container which will contain the
per list attributes.
(imported from commit 26b1f0d2c72d6288a6d3e7ed5f8692426f2a97ad)
Brock Whittaker
Brock Whittaker
Umair Khan
Jason Michalski
Leo Franchi