CLI update

[nichwall]

This adds the cli/CLI.py wrapper, which allows the application to be run either with or without a GUI with equivalent features, discussed in #28.

The download function was moved from gui/GUI.py to the Downloader class to reduce code duplication. Additional work should be done to simplify argument passing to the Downloader class, but would be done in another PR.

To enable the CLI, the argument --nogui needs to be passed in. If it is not passed it, the GUI will be run and all other arguments will be ignored.

[Oshan96]

Thabk you for the changes. Just one quick question. Have you tested for any downloads?

[nichwall]

I did not test every site, but tested a few (using One Piece as the show). I have not tested any requiring captchas yet.

Some sites worked and some did not work. I double checked the sites which didn't work with the current commit of dev and they did not work there either, so there's other issues that need to be resolved. I can open some more issues today for other problems I encountered while testing this PR.

[Oshan96]

Thanks for the update :D

PR seems to be good to be merged so far. I will do the final tests on it and will merge :)

[ArjixWasTaken]

I think this PR was meant to be merged but you forgot to?

[Oshan96]

Hi, @ArjixGamer I'm really sorry that I was not able to merge this. The reason is, I was working on a new features for the 2.0 release of monkey-dl. I was hoping to merge this PR once I was done with those changes to avoid any collisions with the work I've been doing (Since this PR has too many changes I need to try and sort out. Also I was reviewing the code changes of this PR as well). However, I got extremely busy with my work/university and actually had no time to invest on monkey-dl. I still have lot of issues I need to address here, and I'm aware that almost all the sites need to be fixed.
Hoping to at least do some quick fixes to those, but the thing is analyzing the changes and fixing the scrapes takes alot of time which is hard to find for me these days. Hopefully, I will manage to at least get a couple of sites working soon!