[ #7876 ] Remove unused class attribute, rename all attribute use use m_ for private member, m_p for private pointer, m_s for private static and m_sp for private static pointer

[ #7876 ] Update copyright from 2010 to 2012 (next version wont be released until then, so why not doing it now)

[#7023] Add the ability to load an abstract contact backend in the library to resolve more data, polish code

Fix memory leaks in client
Change a bit dbus protocol: int -> int instead of int -> string -> string -> int
Remove unused and empty yamlengine

[#7021] Refactor KDE client dbus handling, add a missing call in daemon and port the DataEngine to the new API