Merge pull request #565 from jonnywilliamson/master

Some small bug fixes
Fixed event listener legacy adapter error
Merge branch 'master' of https://github.com/venomous0x/WhatsAPI
Added bulk
Video Preview

should install ffmpeg for the method to work successfully
fixes broken link in readme
Merge pull request #597 from bartj3/fix/readme

fixes broken link in readme
Changed node reader to streamed

Read 3 bytes (header) > calculate message size > read message > read 3
bytes etc.
As opposed to "hurr durr read ALL bytes and see what I'll find"
Removed old contact sync files (deprecated)
Merge pull request #592 from manufuentescr/patch-4

Video Preview
Added check for ImageMagic and FFMPEG installation

Still uses generic pre-rendered thumbnail as fallback if one of the dependencies is missing
Also inb4 syntax or code errors. I uses the browser editor for this commit :')
Added new KeyStream class
Added new TokenMap class
Removed old KeyStream class
Removed old token dictionary
Renamed custom pdkdf2 function
Updates for WAUTH2 using new classes
Fixed TryGetToken to return int value
Fixed sending unencrypted data

Still need to fix encrypted data
Fixed RC4 ciphering