We now include whether the message was a private or group private
message; this is particularly important with the new setting to
disable including any message content in these emails (since in that
case, one doesn't know anything about the message types).
In this commit we add support for some tags which are also called
void-elements according to
http://w3c.github.io/html/syntax.html#void-elements to be parsed by
our template parser and get tagged as singleton_html_tags.
Fixes: #8387.
Not sure why we have `overflow-y: scroll` in `messages` container in
missed messages email template when it is not a fixed width container
but anyway changing it to `overflow-y: auto` seems to be a safe change
as it will remove the ugly looking inactive scrollbar that was being
displayed there besides the `messages` container without changing the
functionality(if any).
Tim Abbott
YJDave
Aditya Bansal
Harshit Bansal
Rishi Gupta
James Rowan
Vaida Plankyte