Add man/kramdown-man.1.md to the extrafiles.
Explicitly use kramdown.
Added specs for convert_codespan.
Added specs for convert_strong.
Added specs for convert_em.
Convert ndash's back into --.
Added specs for convert_p.
Added specs for convert_comment.
Remove ending \n from codeblocks.
Added specs for convert_codeblock.
Added specs for convert_blockquote.
Added specs for convert_abbreviation.