Classes 3.6 Friends, 'friendly' functions.
Initial commit: Examples and exercises from Chapter 2 and first example from Chapter 3.
Completed 3 exercises. Added executables to .gitignore
Removed generated files from tracking.
Removed more generated files from tracking.
3. Classes - Exercise 4
Minor: Fixed some indentation.
3. Classes - Exercise 5: Is is possible to write something like foo.method1().method2() ?