Classes introduction

[lucaparisi91]

The ordering is a bit off , with concepts being introduced before they are explained:

• move public / private to before talking about constructors
• Explain better the concept of overloading and polymorphism before talking about operators
• Explicit example of difference between const double * p and double * const p .
• && references are a bit misleading in the way they are presented

I find the split with RAII talks ( please expand the acronym ) confusing.