Merge pull request #2591 from trounce1/20720

Added -m 20720 sha256($salt.sha256($pass))

docs/changes.txt

@@ -93,6 +93,7 @@
 - Added hash-mode: Umbraco HMAC-SHA1
 - Added hash-mode: sha1($salt.sha1($pass.$salt))
 - Added hash-mode: sha1(sha1($pass).$salt)
+- Added hash-mode: sha256($salt.sha256($pass))
 
 ##
 ## Features

docs/readme.txt

@@ -112,6 +112,7 @@ NVIDIA GPUs require "NVIDIA Driver" (440.64 or later) and "CUDA Toolkit" (9.0 or
 - sha256($salt.utf16le($pass))
 - sha256(md5($pass))
 - sha256(sha256($pass).$salt)
+- sha256($salt.sha256($pass))
 - sha256(sha256_bin($pass))
 - sha256(utf16le($pass).$salt)
 - sha384($pass.$salt)