Update head to high resolution simulation model.

- Collada visualization geometries with color, normal and specularity maps.
- Low-poly stl collision geometries.
- Approximated inertia tensors.
Update arms to high resolution simulation model.

- Collapse right and left arm geoemtry files into single files (one for both sides).
  Default geometries correspond to the left arm.
  Right arm geometries are obtained by applying a [1 1 -1] scaling (z-axis
  reflection) in the URDF.

- Collada visualization geometries with color, normal and specularity maps.

- Low-poly stl collision geometries.

- Reorder urdf link/joint sequence.
Fill gap between arm_2 and arm_3 with a dummy cylindrical link.
Fix wrong translation for arm_1 axis.
Update torso to high resolution simulation model.

    - Collada visualization geometries with color, normal and specularity maps.
    - Low-poly stl collision geometries.
    - Approximated inertia tensors.
Bumper visualization geometry made minimal.
Update base to high resolution simulation model.

- Collada visualization geometries with color, normal and specularity maps.

- Low-poly stl collision geometries.

- Update dimensions.

- Rearrange front bumper locations.

- Change caster geometry.
Reduce drive wheel width.
Add Gazebo color spec to arm_3_internal_link.
Add color maps with blue details.
Add commented-out reference to blue color maps.
Hand collision geometry no longer generated.
Collision geometries are no longer auto-generated.

- Removed dependencies on convex_decomposition and ivcon packages.

- Propagate changes to ignored folders and package/stack dependencies.
Update base inertial params. Improve bumper layout.
Add Gazebo material property to laser scanners.
Add REEM-H3 hand description.

- Not using production visualization/collision geometries, but temporary STLs.

- Inertial parameters other than mass not yet set.

- Joint ranges have to be confirmed.
Add tool frame to arms, parent attribute to arm xacro.
Move base_footprint visualization to a place where it is not visible.
Resize cargo collision geometry.
Tweak joint dynamics (ad hoc).