HTML5 Goodies

This adds support in various spots for some of the new HTML5 input types.

Added support for new settings types based on HTML5 input types in the profile and admin center
Most (if not all) numeric fields should now be using the "number" type (including "float" and "int" settings)
E-mail field in the profile uses the "email" type
Website URL field in the profile uses the "url" type
Registration date field in the profile and admin member search uses the "date" type
Search boxes (index.template.php, search page and PM search) use the "search" type

More will likely come later.