MAINT: Use more exact boolean checks for pandas structures.

To prepare for being compatible with pandas==0.13.0, which is stricter
on boolean checks.
BUG: adjust benchmark events to match market hours

Previously benchmark events were emitted at 0:00 on the day the
benchmark related to: in 'minute' emission mode this meant that
the benchmarks were emitted before any intra-day trades were
processed.

See: https://github.com/quantopian/zipline/issues/241
BUG: ensure perf stats are generated for all days

When running with minutely emissions the simulator would report to the
user that it simulated 'n - 1' days (where n is the number of days
specified in the simulation params).  Now the correct number of trading
days are reported as being simulated.
BUG: NoopAlgorithm requires initialize().
Merge branch to adjust benchmark times in minute mode.
ENH: Add hdf5 and csv source.

This creates a data source for csv and hdf5 files, a generator to create a sample csv, and a pytables generator to go from a list of dated gzipped csv's in a directory to a pytables data source.

This does not add a unittest yet which we should write for the future.
BUG: Python 3 fix.