improve comment block appearance
improve example block appearance
improve listing block appearance
give comment and example blocks content names
give literal blocks nicer scopes, improve regexes
specify block internal content name more regularly, use meta instead of markup
give open blocks nicer scopes, improve regexes
smarter scope for source in listing block
give passthrough blocks nicer scopes, improve regexes
improve quote block appearance
improve sidebar block appearance
expand test doc a little more
tweak blocks, improving regexes, finer scoping