Fix participants/index_all template
Rearrange helpers
Allow hidden parameters in filtering form
Basic pagination
Paginate participants in Org connexion
Use explicit URL in filter and pagination forms
Add styling for debugging and technical info
fix the formula for per_page
Assign a variables for filtered participants

Keep all filtered participants in `@filtered_participants` variable.
Show participant count and SQL on the index page
Add a workaround for the ActiveRecord count bug

See https://github.com/rails/rails/issues/9458 for details.
Improve form input fields
More page buttons in paginaiton
Minor formatting of filtering form
Set better HTML classes for some buttons
Work on CSS
Move filter form styles to a separate file
Create styles for pagination
Some work on pagination form
paginating_form: show per_page value, move around