Updated gitignore to correctly ignore the build folder.
Added the PublicInformation structure.

The PublicInformation structure contains the user's public information,
available to anyone.
Added the PrivateInformation structure.

The PrivateInformation structure contains the user's private data,
available only to him/her.
Declared metatype.
Added the Status class.

The Status class encapsulated a user's status and status message.
Added c++11 support.
Declared status metatype.