Tidy up HTML errors in INDEX.PHP

Without any "widgets" selected, INDEX.PHP (i.e. the "dashboard")
produces 230+ HTML errors, so:

Remove the "closehead" php variable
Close INPUT, BR and IMG tags
Add ALT parameter to IMG tags
Add CDATA sections to SCRIPT tags
Heading tags cannot contain DIV tags
Merge pull request #429 from ExolonDX/master

Tidy up HTML errors in INDEX.PHP