Thumbnails cache and size

[Ninja_Gah]

I would recommend using list mode if you have hundreds of files in a single folder (you can keep the view mode on auto and it'll show folders in list mode if there are many books). Comics++ was always meant to be a lightweight reader managing thumbnails creates too much maintenance overhead for the app. Also pdf files are the slowest because we rely on Microsoft's pdf library (it was readily available and was easy to add), but it is super slow. We may use an alternate renderer in the future.