updated for version 7.4.171
Problem:    Redo does not set v:count and v:count1.
Solution:   Use a separate buffer for redo, so that we can set the counts when
	    performing redo.
Added tag v7-4-171 for changeset beb037a6c270
updated for version 7.4.172
Problem:    The blowfish code mentions output feedback, but the code is
	    actually doing cipher feedback.
Solution:   Adjust names and comments.
Added tag v7-4-172 for changeset 391e10afccf6