Improve the authentication e-mail message from plxmail.com

[kgracey]

The current authentication e-mail looks like this:

Dear s3robot,

Please go to http://blockly.parallax.com/blockly/confirm?[address removed] to confirm your email address.

If the url does not work, please go to http://blockly.parallax.com/blockly/confirm and enter your email address and the token: [token removed]

The Parallax team

I think we could provide a more informative greeting and still include the key information. Should it have links to the tutorials? What about the Educator Hotline? What if you have real trouble and can't get this login to work? Post your ideas here and I'll improve the message by December.