#12 Change to SI units

[Radu Bogdan Rusu]

Change everything to SI units. Example: angular
velocity should be rad/s not deg/s. A good reference
web site is: http://www.export911.com/ref/unitSI.htm.

[Paul Fitzpatrick]

Logged In: YES
user_id=611078

YARP policy is currently to use SI units for everything
except angles. We use degrees because they are more human
readable/writable than radians. This does introduce
potential conflicts, but we've tried using radians in the
past and it has a cost too in ease of comprehension. I'll
leave this request open to remind us of this issue which we
may want to revisit.