AudioFile => File
Update play-slick to the latest one
Consider AudioFile as a specialized MediaFile
FileApi => MediaFileApi
Don't provide audioFileName when inserting MediaFile

The audioFileName should be automatically generated when the file will
have been converted using ffmpeg. By default we will not trust any
input.
AudioFilename should be Optional
Add dummy sound conversion actor
Add ffmpeg bin path to the actor
Convert media file to wav file using ffmpeg

wave 16bits PCM (pcm_s16le), 16kHz (-ar 16000), mono (-ac 1)
Comment ffmpeg options
Send the entire MediaFile to the actor
Update status when converting a MediaFile to audio
Update README with correct Play! version
Remove bad copy/paste
Prettify code thanks to @ornicar
Chain actor messages
Launch the diarization process (only first pass for now)
Add the second Diarization phase: cleaning MFCCs
Add GLR based segmentation
Add the full Diarization process