Fix validaton of same-protocol URIs (^//)
Add Calibri to the default font list
Fix validation bugs on Picocon Reg page
Add in -moz-boz-sizing definitions
Add link to pre-registration at top of picocon page
Fix up post reg page to have headings

This also removes the links to the t-shirt pre-sales, and corrects
the links to the ticket pre-sales pages
Line spacing in the CTA on Picocon page
Add widths and heights to images on Picocon 27 page
Fix bad characters and spellings in Picocon 27 History
Convert GOH table to paragraphs in the Picocon 27 History
Reindent picocon 27 history