Moved coarse_utcnow from mongoexp -> utils

The book_time and refresh_time are useful trial elements for keeping track of
time, and it's nice to use them in all Trials objects. Subsequent commits use
them in base and ipy.
tracking book_time and refresh_time in ipy and fmin
reduced print frequency in ipy fmin
Rev to getstate and setstate in IPythonTrials

De-serialization wasn't working because the self.refresh() call was
using _clients, which don't exist right away in de-serialization.

Serialization wasn't working because it was touching the 'ar' field, which is
unused since the recent rewrite that brought in a new scheduling strategy.
Bring in expr_to_config (from smacout branch)

This currently-unused-in-hyperopt function extracts just the hyperparameters
and their conditions from a Pyll graph (e.g. domain.expr). It's used to generate
configuration files for smac, and to generate search spaces for Spearmint.

Currently used in hyperopt-spearmint.