Follows the standard of computeDistance

Choose an explicit name to describe what the algorithm effectively does

Properly handle the geometry data struct

Same as Model and Data

Throw exception when parsing meshes instead of runtime error

Use same name to load urdf model with or without root joint

Explicitly overload buildModel functions to get the same name in the
exposure of functions.
Change of API: buildModelFromUrdfWithRoot and
buildModelAndGeomFromUrdfWithRoot are now replaced by their counterpart.

Start documentation using doxygen.

[unittest] refactored unit tests to locate precisely where the unit tests fail