Make printing of Commands failures more readable

[jonaskoelker]

Example output:

[info] > Labels of failing property:
[info] Initial State:
[info]   0
[info] Sequential Commands:
[info]    1. TakeNumber => 1
[info]    2. TakeNumber => 2
[info]    3. TakeNumber => 3
[info] Parallel Commands (starting in state = 3)
[info]    1. TakeNumber => 4
[info]    2. TakeNumber => 5
[info]    3. TakeNumber => 7
[info]
[info]    1. TakeNumber => 6
[info]    2. TakeNumber => 7
[info] ARG_0: ...
[info] ARG_0_ORIGINAL: ...

(Here "..." is an abberivation.)

[SethTisue]

I'm wondering if we should just merge this, even though nobody has stepped forward with a close review. The changes only affect printing, so that doesn't seem high risk.

@jonaskoelker is it worth considering adding test coverage for this...?

[ashawley]

Yes, I think this is a low risk change, as well. Tests would be a good idea, but adding tests for outputs is difficult the way the Commands API is currently written.