Error document now has a link to new frontpage

Certainly while people's caches are yet to be redrawn, don't want it
putting people to the old one without knowing the new one exists.
Consistency across quotes pages.
Merge remote-tracking branch 'origin/master'
Support rewriting betwen .html and .php
Remove index.php/.html from urls
Make various source files static .htmls
Fix a Futurama reference
Fix page links on Picocon 12 History page
Make Tube line colours clearer on Picocon page