Adds tail_before_final_tag option (ex. <p><span>something</span>...</p>)
Adds comments: true feature for handling html comments, also parses <br /> and <img /> elements correctly
Fixes mispelled method name
Asserts filtered attribute is filtered out of parsed result
Updates README to include tail_before_final_tag and comments options
Adds count_tail option to include tail in estimated string length (defaults to false)
Updates README for count_tail feature
count html entities as one character
Merge pull request #3 from rewinfrey/master

Adds tail_before_final_tag and comments features with specs / Updates README