Issue #110: file upload
Issue #124: showing class name in transcript and refactoring class schedule and other uses of course name
Fix insertion on multiple courses

Adding flag to control multiple enrollments on the same course.
Adding restriction to allow class enrollments only on specific classes.
Merge branch 'issue/123_restrict_multiple_class_enrollments' into 3.3.x

Conflicts:
	config/locales/pt-BR.yml
Merge branch 'issue/123_restrict_multiple_class_enrollments' into 3.3.x
Issue #123: passing tests
Merge branch '3.3.x'
Issue #110: Merge master and logo and upload logo file
Issue #110: creating, saving and visualizing pdf header variable
Issue #110: using pdf_header variable, changing variable directory
Issue #110: ignoring image dir
Issue #109: course name
Issue #109: edit course_name
Issue #110: renaming custom variable name to description
Applying 3.3.x fixes to 4.0.x. Step 1
Applying 3.3.x fixes to 4.0.x. Step 2