mark view helpers and generated javascript code as html_safe

Conflicts:
	app/helpers/admin/snippets_helper.rb
	app/views/admin/pages/_node.html.haml
mark view helpers and generated javascript code as html_safe
More view fixes; form_for and html_safe
Various XSS fixes

* page.rb: Escaping snippets/layouts
* standard_tags.rb: r:link, r:breadcrumbs, r:children
* radius_patch.rb: Override radius to ensure tag.expand is html_safe
* lib/radiant/taggable.rb: escape all tags