Adding dtMesh a simple class representing a triangle mesh
Adding .obj loading (from a file or from a memory buffer)
Adding an axis aligned bbox computation method on dtMesh
Import the existing ChunkyTriMesh from RecastDemo to DetourNavmeshCreator

- Using int for the faces to facilitate retro compatibility
Introducing DetourNavmeshCfg, defining navmesh generation configuration

- At the moment only supports tile navmesh with the same configuration for all tiles
Introducing the actual navmesh creation functions

- At the moment only support the creation of tiled navmesh
Allow the configuration of offmesh connections in dtTiledNavmeshCfg
dtCrowd::init now only requires a const navmesh
Making the crowd tests rely on DetourNavmeshCreator
Renaming `DetourCrowdTestUtils` to `Utils`