Improve and polish pycaffe

- fix input preprocessing configuration in 3cac223 picking up on #733
- update examples' outputs given correct preprocessing 9d7346b, always include caffe pythonpath 45d74bd, and reword classification + time on a gtx 770 fc01ee6
- add console output with human-readable labels and a grayscale flag to classify.py courtesy of @petewarden's #735
- fix #525 by scaling data to [0, 255], doing mean subtraction, and then input scaling
The change in #735 was a copy of the original code in the web demo example that I copied the label output from:
https://github.com/BVLC/caffe/blob/master/examples/web_demo/app.py#L128
I've no attachment to the use of pandas, I just assumed there was a reason for its use in web_demo that might also apply here.