DUNE/Entities: added Ricardo Martins as the original author of most of the StatefulEntity code.
DUNE/Tasks: added Renato Caldas to the authors of Task.
DUNE/Entities: fixed namespace documentation.
DUNE/Entities: export BasicEntity and StatefulEntity symbols, as well as functions in EntityUtils.
DUNE/Tasks: fixed whitespace.
DUNE/Entities: fully documented BasicEntity class, improved const-correctness.
DUNE/Entities: fixed function documentation in EntityUtils.
DUNE/Entities: fully documented StatefulEntity class.
DUNE/Entities: documented the EntityDataBase class.