Added HtmlPretty module.
Added HtmlPretty module.

(Warning: module not tested due to failings of my development environment.)

jgm/blaze-html,dylex/blaze-markup,mikehat/blaze-all,mikehat/blaze-all,FranklinChen/blaze-markup,iblech/blaze-html,FranklinChen/blaze-markup,mikehat/blaze-all,jgm/blaze-html,Soostone/blaze-markup-haste,dylex/blaze-markup,Soostone/blaze-html-haste,iblech/blaze-html,Soostone/blaze-markup-haste,jgm/blaze-html