Set our vps as new online server.
Removed 'can use existing stkaddons' account from message.
Fixed server version to be 2.
Added certificate for our vps.
Merge remote-tracking branch 'origin/master' into new_server

Conflicts:
	src/online/http_request.cpp
Updated the URL to work with new server configuration.
Disable CURLOPT_SSL_VERIFYHOST on OSX, since it doesn't work (with
osx's curl version at least).
Removed option to disable CURLOPT_SSL_VERIFYPEER, since it's not needed
anymore.
Switch from IP address to addons.supertuxkart.net (including new
certificate).
Merge remote-tracking branch 'origin/master' into new_server