Log message:
Use standard location for LICENSE line (in MAINTAINER/HOMEPAGE/COMMENT
block). Uncomment some commented out LICENSE lines while here.

Log message:
Import ddrescue-1.8.
Based on PR 39202 by Edgar Fuss, some fixes and improvement by me. 

GNU ddrescue is a data recovery tool. It copies data from one file or block
device (hard disc, cdrom, etc) to another, trying hard to rescue data in case
of read errors.