added HTML5 username pattern attribute in input field
additional username > 2 characters check in registration & username edit
all db-saved user submitted content is now cleared from javascript/html code via htmlentities() to prevent cross-site-scripting attacks
changes June 1st 2013
removed password max. limit
spelling corrections in the comments/readme/changelog, thanks to GrahamCampbell for the corrections [issue #68]
changes June 1st 2013