when running portable version of fastflix, download ffmpeg into the app executable's directory instead of appdata

[glodomorrapl]

fastflix does allow you to change the path to ffmpeg and ffprobe (btw, any reason these two are separate and not just one path to a folder?), but if you change these paths to something else and then use "download newest ffmpeg", the paths reset to appdata. i don't think this is desired behavior for a program running in portable mode.