Overrode homepage_url to ensure returned URL is valid

There are several company homepage urls that do not begin with the protocol http:// or https://. 6kites is an example of the issue. Their string returned by the attribute homepage_url on Company is www.6kites.com. When haml generates the href it assumes it should generate a relative url http://www.bdnewtech.com/www.6kites.com. This generates a 404. It's a small but annoying problem.