Mail template

Ok, implemented the template so it now can be used by action mailer. Converted the view to haml for easier viewing. Made some other cosmetic changes :)

One thing I am not happy about is those inline styles but they were already in template provided on dropbox. That could be later dealt with as it is possible to inject those inline styles for mails dynamically and they can be on external stylesheet.
Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.