Adding Sebastiaan's index.php, which is optimized for search engines.  Also removed a newline from save-fancy.lisp for dumb reasons
Merge branch 'master' of https://github.com/ragerdl/acl2
Merge pull request #308 from ragerdl/master

Merge in SEO'd index.php
Parameterizing BOOK_PARALLELISM_LEVEL for build-multi.sh
Bringing in Sebastiaan's SEO scripts (again) and parameterizing BOOK_PARALLELISM_LEVEL in build-multi.sh