Enter key

I just added "Enter" key support to the message list such that pressing Enter will open the message.

I also learned a bit more about obscure behavior in selecting/double-clicking/dragging messages with various mod keys (shift/ctrl). Did you know that Outlook, Outlook Express and Thunderbird all behave differently when you click-and-hold on a message when the control key is held? Me neither. For the record Roundcube now emulates Outlook 2003 behavior. I won't go into the details, suffice to say you'll probably never notice the difference (but by-gum it's now "right"!)

-Charles