resources: add a shared constants xacro.
m10ia: update urdfs based on DH data. For #54 and #63.
m16ib: update urdfs based on DH data. For #54 and #63.
m430ia2p: update urdfs based on DH data. For #54 and #63.
m430ia2f: update urdfs based on DH data. For #54 and #63.
support: add 'base' link (transform to World Coordinates). Fix #101.

This should not affect existing kinematic plugins or MoveIt configurations:

 - the link is not part of the main kinematic chain
 - the transform is implemented as a fixed joint
m430ia2f: fix mirrored meshes. Fix #109.
Update readme.
all: fix indent to follow ROS styleguide. Fix #118.
Experiment with KAREL motion interface.

Small test with the (deprecated) KAREL MOVETO and related instructions. By
specifying a SEG_TIME we let the controller approximate ROS-I command
velocity for the current trajectory segment.

TODO: test performance objectively.
TODO: do this with TPE.