Preparation for ffmpeg_updater
Pseudo code and add some logic with file Version
Comparaison of the versions functionnel, working on the integration of FileDownloader in ffmpeg_downloader class
New ffmpeg_downloader class, better organisation of the code, the ffmpeg version is now downloaded and checked with the Plug&Stream API, some errors are now better handled, merged the old FileDownloader class. Referenced by #9
Added testing protocols for ffmpeg
adding QUrl for Windows and Linux
Unification of the code, with precise 'defined(xxx)' macros
Corrected a bug that block the interface when a stream is occuring. We should not wait the command line to 'wait for finished', but for 'wait for started'. We should certainly spawn this process in aseparated thread to avoid it to freeze the interface.