||represents a one css item, consisting of a css selector and rules
for that selector
||parses a css block that is found in between style tags, or referenced
from an external link tag.
||a comparator that orders CssItems based on the selector
Id selectors have highest priority, followed by class selectors,
then path selectors, and finally single element selectors.
||the basic servlet that handles requests to convert web page html
to email html
||the main processer for converting web pages to email pages
||resolves entities around html strict, transitional and frameset dtds, along
with the entity definitions so that the code doesn't access the w3.org definitions,
which will deny access with 503 errors.