[builder] Extended significantly the Armature builder helper

In particular, it is now (rightfully) a subclass of actuator, and it supports
adding IK targets to drive specific bones.
Add support for IK in armatures

Kinematic chains can now be controlled via inverse kinematics
by placing/moving so-called IK targets that are tracked by your
armature.

A new service (Armature.place_IK_target) allows to instanteanously
place and orient an IK target, while the asynchronous service
Armature.move_IK_target allows to move at a given speed the target.

The list of IK targets available on a given armature can be obtain
with Armature.list_IK_targets.

To easily create the IK targets, the morse.builder.Armature offers the
create_IK_targets([joints]) that can be called in Builder scripts.

Note that internally, all rotations are handled as quaternions to
ease interpolation over time.

While here:
- removed the IK constraint in KUKA LWR Blend file
- added (from Python) an IK target to the KUKA LWR. Cf
  morse.builder.actuators.KukaLWR
  to see how this is done.
- updated testing/base/armature_testing
[doc] Updated RELEASE notes to mention IK targets
[doc] Mention IK-based (aka, cartesian) control of armatures
[sensor] cleanup Kinect still WIP

The idea is to use ROS' depth_image_proc package to mix depth and rgb
images, instead of converting the OpenGL Depth (Z) buffer to an XYZ
point-cloud, we send a float32 depth image as the kinect does (it sends
uint16 instead, just have to skip `depth_image_proc/convert_metric`[1]).

[1] http://wiki.ros.org/depth_image_proc#depth_image_proc.2BAC8-convert_metric

As mentioned in #419, the launch-file is still a work in progress,
included here as a base for future work.

[#419] https://github.com/morse-simulator/morse/issues/419
[test] add missing import math
[data] add basics without logic
[builder] add helper to convert .blend to pure py

at least logic and empty objects (for now)

add setup replacing basics.blend (logic part)
reload morse.core.blenderapi in setup fix #405
remove MouseSensor.use_pulse, was not in 2.63
set render fps to 25 (default:24)
import at the top
[camera] workaround scene not in list