second part of lecture 3: OOP
part 1 of lecture 3: closures
Merge branch 'master' of https://github.com/MarcDiethelm/fe-lectures

# By Marc Diethelm
# Via Marc Diethelm
* 'master' of https://github.com/MarcDiethelm/fe-lectures:
  part 1 of lecture 3: closures
  second part of lecture 3: OOP