[doc] Mention pymorse option for homebrew

While here, fix some typos
[wheeled_robot] Try to computer properly the wheel radius

In particular, it means that you do not want to consider the radious of
the CasterWheel if any.
It improves a lot the behaviour of pionner3dx
[builder] Fix the #421 fix :)

It breaks completely the morse wheeled robot in the pionner3dx case (two
wheels, one caster wheel). The new version works properly for 4 wheels
robots and 2 wheels robots + caster
[core] Make FixTurningSpeed robot generic for Physical Robot
[builder] Provide relevant FixTurningSpeed for various robot

These values are based on experimentations, I still do not understand
what cause the issue between the 'expected model' and the 'really
simulated model'
[testing/segway] Test with the default FixTurningSpeed
[testing] Relax constraint on two_segway test

The new value are more in sync with the standard segway test
[testing] Various "improvements" of pionner3d test

Remove print
Fix call to send_service_speed
Adjust slightly precision requested for the initial pose test
[actuator] Move apply_vw_wheels in MorsePhysicsRobot class

Use this definition in both keyboard and v_omega_diff_drive  (code --)
Force the speed at (0.0, 0.0) in the construction, so the robot won't
move in an arbitrary way. Should fix #444.
[core] Add a way to retrieve gravity

While here, use it in imu instead of guessing
[pymorse] Call the correct service in reset()
[testing] Add some regression test for service on human

Reported by Florian Lier on morse-users@
[builder] Update config properly when robots are renamed in close_context

It fixes the issue about service configuration for human reported by
Florian Lier on morse-users@
[ros] remove /base_image addition from camera frame_id
[middleware/pocolibs] Adapt to velodyne-1.4 interface
[ros overlays] JointTrajectoryAction is now available in control_msgs
[human builder] Use standard armature/armature pose

Instead of the 'LAAS centric' HumanPosture (which is still used with the
pocolibs middleware).

Also, the armature sensor is now automatically added. This issue has been reported
by Omar Adair Islas Ramírez on the mailing list.
[ros] {ROSReader->ROSSubscriber}

Be more consistent with ROS terminology.

Reported by Diego Escudero
[ros] Prevent registering ROS services with no explicit type

The type is expected to be set with @ros_service(type=...).
This replace previous behaviour where ROS service would default
to (the most useless) 'MorseAnyService'. Cf commit 07ac80117a162ce for details.

Reported by Diego Escudero
{ROS,Yarp,... -> ROSDatastreamManager,YarpDatastreamManager,...}

Refactoring of datastream manager name, to match the 'xxxRequestManager'
terminology. As a side effect, it prevents confusion between a
'core.datastream.Datastream' (renamed into DatastreamManager) and
a 'middleware.abstract_datastream.AbstractDatastream' which are two
unreleated objects.

Reported by Diego Escudero.