Usage: $this->user->Faculty->ID or $this->user->Faculty->getDisciplines()

* Moved some static methods to Factory model
* Removed unused param $teacherID
* Assertion checks moved to models

Use RusLang::tr() function instead.

Field Model_Factory::ID came public, new method getStudents() added.
Renamed Model_Students::searchStudents() to search(); removed duplicate method NotAttendingDiscipline().

– Type constants (exam, credit)
– New function exists()
– More clear method names

1) fix Rating Model
2) sql CreateSubject: restore expected behavior (see todo in commit "Refactoring of subjects upload page" 19.06.15)
3) refactor and disable JavaAuth (see todo)