Added multiple order printing following merge.
Change page title to list order IDs in case of multiple printing, changed <body> to include #shopp and .class. Removed unnecessary wrapping div.
Merge branch 'master' of https://github.com/ingenesis/shopp into print-receipts

Conflicts:
	api/theme/checkout.php
Ensured iframe for order printing is not visible.
Tidied comments
Removed out-of-place changes to month and year label options, ready for a new branch and PR.
Removed out-of-place changes to month and year label options, ready for a new branch and PR.