Add the 2 new legacy managers to the readme.

README.txt

@@ -5,7 +5,7 @@ Password Manager
 This package provides a password manager mechanism. Password manager
 is an utility object that can encode and check encoded
 passwords. Beyond the generic interface, this package also provides
-four implementations:
+six implementations:
 
 * PlainTextPasswordManager - the most simple and the less secure
   one. It does not do any password encoding and simply checks password
@@ -28,6 +28,16 @@ four implementations:
   when encoding it. This password manager is compatible with passwords
   used in LDAP databases.
 
+* CryptPasswordManager - A manager implementing the crypt(3) hashing scheme.
+  Only available if the python crypt module is installed. This is a legacy
+  manager, only present to ensure that zope.password can be used for all
+  schemes defined in RFC 2307 (LDAP).
+
+* MySQLPasswordManager - A manager implementing the digest scheme as
+  implemented in the MySQL PASSWORD function in MySQL versions before 4.1. 
+  Note that this method results in a very weak 16-byte hash.
+
+
 It is strongly recommended to use SSHAPasswordManager, as it's the
 most secure.