Connect the database at "compile time"

Connect the database at "compile time" to allow setting constants based on database column types (which have to be dynamically inspected).
Simplify download action
Do not use ORG_PAGE_PREFIX constant (:'org/')
Simplify filtering in route handlers
Experiment with CSS for data attribute values
Fix translations: do not use reserved key

Do not use reserved option key 'object' as an interpolation key, use 'obj' instead.
Improve 'show', 'edit', 'new' view templates
Do not show logos in organiser interface
Improve filtering form code structure
Autofocus "Last name" filtering form field
Remove forgotten file
Do not forget to order participations by conf
Add 'header_from_attribute_name' helper function
Work on participant views ('show', 'edit', 'new')
Use empty values for absent request params

Do not expect all params be submitted, use default values if absent.
Use functions to process params for 'edit' action
Use 'attribute_name' instead of 'attribute', etc.

Use "attribute_name" instead of "attribute" and "association_name" instead of "association" where appropriate.
Move common participant form fields to a partial

Move common participant create/update form fields to a partial.
Don't nest talk proposal fields in participations

Do not nest talk proposal fields in participations fields in creating and updating participants.
Add missing 'set_locale' calls