Added the lessons menu.
 On branch master
 Changes to be committed:
	modified:   bin/Debug/schoolMarkLogger
	modified:   competence.cpp
	modified:   competence.hpp
	modified:   lesson.cpp
	modified:   quartal.cpp
	modified:   school_object.hpp
Added the competences menu.
 On branch master
 Changes to be committed:
	modified:   bin/Debug/schoolMarkLogger
	modified:   competence.cpp
	modified:   competence.hpp
	modified:   lesson.cpp
	modified:   school_mark.hpp
	modified:   school_object.hpp