[RFC] vim-patch:7.4.172

Merging vim-patch:7.4.172

Problem:    The blowfish code mentions output feedback, but the code is
	        actually doing cipher feedback.
Solution:   Adjust names and comments.

https://code.google.com/p/vim/source/detail?r=391e10afccf6879dcfab8b28cb1587a13eb835c0