segment: Add an option to prepend a string to the list entries

Useful to generate lists with absolute urls.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
hls: Add an option to prepend a baseurl to the playlist entries

Useful to generate playlists with absolute paths.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>