Feature request: Add timestamps to sample progress

[jerome-white]

When running Stan, I like to follow the sampling output progress; for example:

...
Chain [1] Iteration:  500 / 1500 [ 33%]  (Warmup)
Chain [1] Iteration:  501 / 1500 [ 33%]  (Sampling)
...

It would nice if such sampling came with timestamps so that I could get a definitive sense for how long things are taking. Augmenting the above output, perhaps something like:

...
(Wed Sep 21 10:27:52 2011) Chain [1] Iteration:  500 / 1500 [ 33%]  (Warmup)
(Wed Sep 21 12:18:45 2011) Chain [1] Iteration:  501 / 1500 [ 33%]  (Sampling)
...

Does that seem reasonable? (I am new to the Stan development community, so if not I understand.)