Add support for 'morse import <path>'

This allows to import pre-existing simulations in MORSE
for later run them with 'morse run' (or 'morse edit').

'path' must be a local path.

Partially fix #396
[doc] Added a 'quickstart' tutorial

It illustrates to use of 'morse create' and friends.

Partially fix #396
Implement a template for sensors

Used when calling 'morse add sensor ...'

Partially fix #396
[doc] Document in more places 'morse create|add'

Related to issue #396
Removed non-standard ROS serialization for KUKA joints

Originally introduced in #301. The normal way to add custom
serialization is now with 'add_stream'. Cf
http://www.openrobots.org/morse/doc/latest/user/builder.html#middleware-configuration
[unittest] Add a test for 2 Segway RMP400

Exhibit a wheel parenting bug due to Blender renaming wheels.
Spoted by Caleb Voss.
[doc] Updated RELEASE_NOTES/what's new
Revert "Removed non-standard ROS serialization for KUKA joints"

This reverts commit c1ae95a1b4a7cf40ffe0711e7226960c127d4f64.

This encoding is in fact 'relatively standard', as it is part of the
ros-orocos interface, and brics-actuator interface.
[doc] add sound to generate_doc
[tools] update components_exhibit to Blender 2.66

Change in Blender 2.66:
scene.render.alpha_mode : {'PREMUL' -> 'TRANSPARENT'}
[testing] Add some unit-test for renaming

In particular, test loop behaviour and so fails (#357)
[builder] Pass the name of the robot in the Robot ctor

Avoid to duplicate code, and only set the name if it not None
[builder] Fix handling of loops in builder script

Fix #357
[doc] Describe how to handle loop at the builder level
[doc] generate_doc load dynamically all components
[doc] Improve generate_doc to generate doc from robot python file
[core] Use add_property instead of reinventing it in wheeled_robot

Moreover, it will ease the automatic generation of robot documentation
(#284).
[test] Add regression test for issue #423
[builder] Fix issue #423

Instead of doing the frame change at the append level, do it at the end
in the after_renaming method. In this way, we don't care about the
relative order between translate(), rotate() and append().
[testing] Use properly morse.testing.testing.main