migration of this template to html5

This switches the template to html 5. Adds a configurable option to add some namespace prefixes for OpenGraph meta tags; this saves plugins that want to use these tags of modifying the template.

Also does some cleanup, eg removing unused icons, spelling corrections.
Merge awesome pullrequest 'mprins-html5'
drop probably outdated makefile
update
Merge branch 'master' into stable