Printing extrema - nan

[gknor]

There is a problem with not-a-numbers. For example if monitored metric (e.g. F1) is nan after first epoch min and max values remain not-a-number during whole training. For example:
F1:
training (min: nan, max: nan, cur: 0.75).

[stared]

@gknor I see. Thinking how to include nans in a consistent.
@kkanska - any ideas on that?

[stared]

Solved by @kkanska - as of current master branch or 0.2.3+ release