[PATCH] git-send-email-script - Fix loops that limit emails to unique values to be pedantically correct.

Email addresses aren't generally case sensitive in the real world, but
technically, they *can* be.  So, let's do the right thing.

Additionally, fix the generated message-id to have the right template used.
Signed-off-by: NRyan Anderson <ryan@michonline.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>