Copy param --save_date_time from big-sleep; Leftpadding sequence with six zeroes; refactoring

[afiaka87]

• Implemented the same functionality as the --save_date_time parameter from your big-sleep repo.
• Made image generation more efficient. Before, two images were generated, one for --save_progress and another for --save_every. Now a single image is generated and copied.
• Now leftpadding the sequence number for image paths with 6 zeros. Should fix alphabetic sorting.
• More python usage in README. Various configurations for different hardware setups.
• Switch print to tqdm.write() in deep-daze.py so we don't interrupt the tqdm progress bar.