Resolve #1298

* use serial.load in CIFAR10._unpickle
* remove "scripts/tutorials/grbm_smd/make_dataset.py" from pep8 whitelist
* refine serial.load for interoparability between Python 2 and 3
* remove N and np, aliases of numpy
merge pickle_load into serial.load
remove devtools.convert_pkl
remove the CIFAR10._unpickle method
Merge pull request #1299 from euphoris/pickle

Resolve #1298