Improvements + Cross compile

We can now compile on both Linux and Windows from the same code without issues

Minor improvement on multithread encode process by reducing number of operations to do

Linux & Windows stable version

Now we have both windows & linux version, here's the build and separate codes (differences are in codecFunctions.c file)

Windows version only

First full and stable working version on windows
Working on the linux one.
Thought I could do some cross platform but some functions (to know file size) doesn't have the same behavior on each system and cause crash on big files (> 2 GB)