Move video thumbnails generation in separate thread.
Merge https://github.com/AnaMes/BBNTMP
Merge https://github.com/AnaMes/BBNTMP
Fixed problem related generating thumbnail file path.
Added functionality to generate thumbnails for newly added videos.
Merge https://github.com/AnaMes/BBNTMP
Merge pull request #27 from Anmeg/master

Move video thumbnails generation in separate thread.