do not create an fe_user for all certified integrators

They now use a seperate model that might later on get
an (optional) reference to the fe_user record
rename FeUsersController to ListingController
make list action more efficiant

by reducing number of queries to database
fix name of user relation in certification
modify conversion script to output sql statements

this makes it easier to import the data during deployment
remove uncached sorting of certified integrators

Rendering the list with over thousand records is
horribly slow. Having that list not cached will
likely kill the whole server. So I removed the feature
for now.