Add Login link when user logged out; add help link
Add help controller, splash, and goals pages
Remove junk comments
Fix for in-page links hidden by nav bar
Add help page images, SQL schema, and ER diagram
Add glossary help page
Help page fixes

- add new pages to controller and help index
- mostly complete: dev-setup.php, using-brovine.php
- complete: freq-itemset-gen.php, sql-schema.php
- not complete: brovine-technical.php