Include video overlays in exports

[libreliodev]

As specified in the Librelio specifications (https://github.com/libreliodev/iOS/wiki/Video-Module), a link should be added in the exported pdf file in the following form: http://localhost/[FileName]?[OptionArgs]

. Depending on the options selected for the overlay:

• if "Play FullScreen" was selected, add warect=full
• if "Auto Play" was selectedd, add waplay=auto

Add the video file in the export directory (don't embed it in the pdf file).