Add link to the addendum page
Add addendum.psp page as created by @JWDebelius

This page was created by @JWDebelius but I formatted it and integrated
it with the current CSS and website.
Add resources for addendum.psp

These resources were gathered by @JWDebelius.
Added a linked certificate

Clicking on plots on the certificate will now take the particiapnt to
the description.
Formatting was also changed so tables and h6 look like text from the
certificate.
Corrects for gramatical changes
Certificate includes css transparancies

Certificate at the top of the page appears with transparancy (hover
over for full color) in Safari. Firefox link version not yet working.
Made opacity work in Firefox/IE
Nuke the cat!

Fixes #536
Modify assign_user_to_studies interface

Make it a bunch of checkboxes instead. This is also ugly, but less error-prone,
and Gail said it would be fine/better.
Merge pull request #553 from adamrp/issue552

Modify assign_user_to_studies interface
Merge pull request #551 from adamrp/issue536

Nuke the cat!
Merge pull request #545 from ElDeveloper/addendum

Addendum