[Localization] Chat i18n enhancements

[Chris Leonard]

On a similar note to that raised by Alexandro Colorado (jza) about
TamTam i18n, I filed this ticket about Chat, which Aleksey (alsroot)
has addressed with the patch linked on the ticket.

http://bugs.sugarlabs.org/ticket/2903

The general idea was to add the actual ASCII-art emoticons tot
developer's comments so that localizers could more easily determine
the appropriate local term for a particular "smiley".

We are working out some logistic issues on how POT regeneration should
occur and make it's way into the Templates project, so these
developer's comments have not landed in the current PO files, but
we'll get there as soon as we can.

cjl