ENH: Better progressbar when downloading data

Old implementation of the progressbar only updates every couple percent points.
With a multi-gigabyte download over a slow connection, it might appear that the
download is not making any progress.  Revamped the progressbar with a modified
version that provides percent complete (down to five decimal places) and a
spinner.  The extra detail makes it clear that progress is being made even over
slow connections.

The progressbar code is adapted from Neurobehavior's cns.io package
(bitbucket.org/bburan/neurobehavior).
BUG: PEP8 fixes
Stylistic changes to commit

* More descriptive parameters to ProgressBar
* Change ''' to """
* Added docstring examples
Merge pull request #545 from bburan-galenea/download-progress

ENH: Better progressbar when downloading data
Merge pull request #547 from dengemann/pandas_git

FIX: support tests for pandas dev version
WIP/API/ENH: create epochs in ICA space

Here I propose two new convenience methods for the ICA class which
allow useres to directly create epochs in ICA space without previous
export to Raw. This addresses #319
FIX: remove unsuited score func test cases.

Closes #315.
ENH: realizing epochs.sources_as_epochs_from_epochs

+ adding to example
ENH: addressing recent discussion
ENH: ... hwat's new
ENH + FIX: addressing discussion + add picked data
CLEANUP example
ENH: take advantage of Epochs ch_names property
COSMITS
FIX: example
ENH: call pick_types correctly
CLEANUP