• fortuna.c: catch up with r278927 and fix a buffer overflow by using the

	      temporary buffer when remaining space is not enough to hold
	      a whole block.

• yarrow.c: add a comment that we intend to change the code and remove

	      memcpy's in the future. (*)

Requested by: markm (*)
Reviewed by: markm
Approved by: so (self)