More modules removal

[alexAubin]

Less is more, remove some modules with debatable usefulness ... :

-- ep_countable - Add paragraphs, words and characters count -- ep_font_color - Be able to change font color -- ep_markdown - Edit and export as Markdown -- ep_spellcheck - Add spell checking -- ep_subscript_and_superscript - Support for subscript and superscript -- ep_comments_page - Add comments on sidebar and link it to the text.