changement du .gitignore pour les projets Visual Studio
Temporary commit (with code example).

Will be cleaned/splitted later. Not tested with cpplint.
Fix confusion on C++ const syntax.
Remove dummy file.
Clean the events definition.
Explicit enum convertion to int.
Implement serialization/deserialization according to the current def. of events.
WIP on the client network manager.
Add a first, very basic, serialization test.
Update gitignore.
Do not use raw pointers in the client NetworkManager.