Version 0.2.8 Released on PyPi

Performance enhancement during recent/on_modify case. Only build the css_text based on new
class selectors created during the most recent modification. Append this to the pre-existing css_text then
overwrite blowdry.css or blowdry.min.css. A new parameter css_text was added to blowdry.parse() and
to the override for the watchdog event handler. Special test created to verify that the css_text is
handled properly.