V2.0.0 integration

First release of MASA's work on recast/detour.

* The interface for the dtCrowd class has been completely rebuild.
* Implementation of the notion of behaviors for the agents.
* Some behaviors are available by default for the user to use.
* The user can create its own behaviors.
* The documentation has been updated and some tutorials have been added.
* The features of the Detour Crowd module have unit tests (more than 100)