Ensure joint angle notation is consistent

[Ian118]

I think I can represent each leg as the same leg (including the mirrored legs) by assigning a different zero to the joints and adjusting the IK/FK. Something to check.

[Ian118]

Had some new thoughts on this, since it's kinda hard to wrap my head around. I definitely need to mirror some of the legs since the motion on the left/right and front/back needs to be reversed (duh). I could either do this in software or in robot firmware config. If I do it in software, it could mess with the FK and IK. If I do it in firmware, I think I could use the same right-front (or left-front, since this uses all positive joint angles) IK to generate joint angles for all the legs.

[Ian118]

Motor Directions:

	Shoulder (1)	Upper (2)	Lower (3)
RF Leg (1)	+	+	-
LF Leg (2)	+	-	+
RB Leg (3)	-	+	-
LB Leg (4)	-	-	+

Debug command to change firmware config (where AB is the CAD ID):

AB>conf set motor_position.output.sign -1

[Ian118]

Going back on this, the code for Screw axes encodes sign information. This can be passed along to IK and Jacobian functions.
I have reset all of the motors' internal directions to positive (ccw).

[Ian118]

The new goal for this issue is to modify the custom kinematics/dynamics functions to accept the same screw axis parameters as the Modern Robotics library does.