In the transition to Template::Toolkit a part of the DOCTYPE includes
got its case switched, making it invalid: XHTML was changed to Xhtml
Correcting the case quiets errors in the validator.
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
previously, it wasn't possible to insert anything into the <head> on
an individual template unless it was the title of the page. Now, the
structure is a bit more flexible to allow additional head elements to
be included.