Added support for SSL, changes a little API in the account-store type

[Philip Van Hoof <spam pvanhoof be>]

Because SSL needs to ask the user whether he accepts the SSL
certificate, I had to change a little API in the account-store API which
you'll have to implement.

It's the alert_func in the account-store interface. An implementation
must ask the user the prompt (passed as a parameter), and must return
true or false depending on the answer of the user.

After that, you can create a "list" in gconf for each account called
"options". You simply add strings like this: "option=value". They will
be added the the url_string which camel will get for connecting.

If you add "use_ssl=always" to that gconf list, it'll connect using SSL.
It will also use the confirmation question (you'll see) to know whether
or not it's okay to connect.

The demo account-store in libtinymail-gnome-desktop doesn't implement
storing the certificates (so that you don't have to ask the question
each time the user connects).

I haven't yet implemented this for transport accounts. But it's more or
less the exact same story. So, soon .. I guess.

-- 
Philip Van Hoof, software developer at x-tend 
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
work: vanhoof at x-tend dot be 
http://www.pvanhoof.be - http://www.x-tend.be