* moved the gsub and strip into a function named normalize_whitespace
* added the call to has_no_content?
* use regex 'any one or more whitespace character' instead of simply removing all newline characters as suggested by @jnicklas and @joliss [#521]
* has_content? should ignore any whitespace in the content being compared (the matcher text) so that comparing whitespace sensitive text i.e. content in a <pre> tag will be matched properly.