Added learn_material.ecpp, a minor fix in the database model
Some small API changes and fixes
Removed semicolons at the end of SQL query strings
Merge branch 'master' of https://github.com/jonessen96/libsmo

Conflicts:
	model/smo.mwb
	src/course.cpp
	src/lesson.cpp
	src/subject.cpp
Merge commit '0f014b4471d884b3925068aabb30c88c614598dd'

Conflicts:
	libsmo/model/smo.mwb
	libsmo/src/course.cpp
	libsmo/src/lesson.cpp
	libsmo/src/subject.cpp