Adds functionality to populate course dropdown list

Adds functionality to populate course dropdown list. Currently it only
uses static values as place holders.
Merge remote-tracking branch 'origin/master'

Conflicts:
	include/Main.h
	src/Main.cc

	modified:   Makefile
	new file:   build/gb.db
	modified:   include/Main.h
	new file:   include/data/student.h
	modified:   include/sql/gbsql.h
	modified:   src/Main.cc
	new file:   src/data/student.cc
	modified:   src/sql/gbsql.cc
	modified:   tests/gbsqltest.cc