Added support for png and gif images, and apng and gif animations.
Write thumbnails in only two possible formats: jpg for static images, gif for videos.
Separate css into new file.
Refactor html newline writing.
Fix bug when identifying file extension.
Add preliminar support for video files
Add support for video files.
Adhere to freedesktop.org Thumbnail Managing Standard.
Add parameters check
Gather and show proper statistics after scanning.
Extract file uri generator.
Fix html paths to images: they used to be absolute, need to be relative instead.
Fix creation of thumbnail directories: was not being handled for video files.
Add obligatory (according to freedesktop.org Thumbnail Managing Standard) MTime and URI png info fields to thumbnails.
Store and show error information in statistics class too (not just the number of failures).
Renamed script to something more appropriate.
Explicit argument explanation through variable name.
Add realtime logging of the scanning progress.
Added fancy colours to the tty interface.
Extract video/image classification into separate methods.