Class based rewrite

Rewrote the base comic scraper such that it will be easier to write extractors to website without tweaking the main code.

Manga download from https urls, with pdf file output

Added https url suppport (speeds up download if behind proxy). Download as either cbz or pdf file formats. Default format set as pdf.

Manga download support with multithreading

Class based rewrite, with added manga download feature and multithreading support. Added numpy to requirements and setup.py to fix pip error.

Manga download support with multithreading

Class based rewrite, with added manga download feature and multithreading support.