Make free_joint_state parsing more generalized

[marrts]

Fixed an issue where the IKFast plugin would fail to parse your free_joint_state list if it looked like this:

free_joint_states:
   - [0.0]
   - [-0.1]
   - [0.1]
   - [-0.2]
   - [0.2]

[Levi-Armstrong]

Does this make sense, because this is allowing something that should a single value to be entered as a vector?

[rjoomen]

It is my understanding it works like this:
One free joint:

free_joint_states:
   - [0.0]
   - [-0.1]
   - [0.1]
   - [-0.2]
   - [0.2]

Two free joints:

free_joint_states:
   - [0.0, 0.0]
   - [-0.1, 0.0]
   - [0.1, 0.1]
   - [-0.2, 0.1]
   - [0.2, 0.2]

But before this PR one had to add indices:

free_joint_states:
   1: [0.0]
   2: [-0.1]
   3: [0.1]
   4: [-0.2]
   5: [0.2]

Etc.

Am I right, @marrts?

[marrts]

Am I right, @marrts?

Yes, that is exactly right. Now it works with either numbers or dashes. This did not effect what the actual passing of values looks like, which is how you describe it.

[Levi-Armstrong]

Thanks for the clarification. LGTM