Add smpt_ssl parameter to force SSL SMTP connection from start.
This is based on a slightly reworked commit from @aswarren (pull
request 198).  I tweaked it by dropping smtp_from (as discussed in
pull request), and fixing a small string versus bool bug.

Tested both ways and it seems to work, with any luck though there is a
bug in there somewhere and Galaxy admins everywhere will get a break
until it is discovered :).