[#118,#120,#125,#131,#134,submit][s]: Disabled autocomplete

Fixes #131 by adding text and changed reqd. attribute of name
Fixes #134 by adding a custom filter to nunjucks environment that adds
urlize filter
Fixes #120 by adding autocomplete off to form
Fixes #125 by adding tooltip and sanitizing URL
Fixes #118 by sanitizing URL