fix compiler error when hash sha256 is turned off; add HASH_KW to condInput; add --hash [md5 | sha2] to iput; the --hash switch should always be used in combination with the -K command line switch

git-svn-id: svn://irodssvn.ucsd.edu/trunk@5629 ea137bd6-aa86-47b6-b90d-b101d9f19a90