Added the static user::create() function.
TODO: Creating school years immediately (in the user::create() function).
 On branch master
 Changes to be committed:
	modified:   bin/Debug/schoolMarkLogger
	modified:   main.cpp
	modified:   menu.hpp
	modified:   school_year.hpp
	new file:   user.cpp
	modified:   user.hpp
	modified:   vector_owner.hpp