check and error if any are different. The error message from xdelta when
a source file doesn't have the right checksup is fairly obscure and
doesn't aid in fixing the problem.
+
+ There's an implementation of this in the manifest-md5sums branch of
+ git://git.debian.org/git/users/kibi-guest/pristine-tar.git , but I have
+ not yet decided about applying it, since it would bloat the delta files
+ with a list of all the files and md5sums..
* bzip?