New method to check if it can be downloaded
A lot of changes

Too much to describe here. @hatboysam I have done pretty much all of
your request.

Logic changes :
- Public methods start with a capital letter
- Private methods are grouped together
- Private static methods are grouped together

Some changes :
- Made private what had to be.
- Created better and easier methods for Sending Snap, Video or Stories.
- Better way to get Friends, Stories, Snaps,..
- Reduced the amount of time JSON was parsed.
- Much more.