add handler-method for filter action requests
implements a redirect-builder and use them
add test for RedirectBuilder and fix them
UserService accept a parameter for "attributes" in searchUser
code styling
add tests for filtering
rename SessionData and move them into a subpackage
remove old SessionData class
save filter configuration into session and read from them
encode filter query
the RedirectBuilder can now handle single parameters
implements handling for userlist-sorting
fix testdata (user references to names)
fix test for multiple filtering in user-list
remove unused constructor
add Integrationtests for sort the user-list
implements limitation of user-list
add integration tests for limitation of user-list
code styling
implements paging