Log Message:
dvdauthor: update to 0.7.2

Depends on ImageMagic6 due to use of deprecated interface.

0.7.2: 2016 December 31
	Various code-quality and build improvements
	Support "jump pgc n" and other interaction code-generation improvements
	Improve reliability of dvdunauthor
	Don't force infinite pause on last cell of a PGC
	Allow specification of provider field in VMG IFO file
	Add video_format(7) man page
	Add padding to ensure .BUP and .IFO files end up in different ECC blocks
	Enabled hinting of rendered subtitle text
	Require cell start and end times (if specified) to be nonempty