Make the pages work as JS templates

- Stop doing the extra fetches for the pages on the backend
- Load the panel content from the appropriate page
- Import everything from jstemplates/pages/ in the index template
- Update the documentation to reflect the new style
- Update all of the included flavors

NOTE: The ids of the page templates begin with 'pages/'. A slash ('/') is technically not a valid character in an element id, according to the HTML spec. It works for now though. Keep an eye on it.