Document the new feature implemented by Andrea Biancini to add friendly names...

Document the new feature implemented by Andrea Biancini to add friendly names to attributes in the SP's metadata. Solves issue #60.

modules/saml/docs/sp.txt

@@ -99,6 +99,10 @@ Options
 :   The attributes will be added without a `NameFormat` by default.
     Use the `attributes.NameFormat` option to specify the `NameFormat` for the attributes.
 
+:   An associative array can be used, mixing both elements with and without keys. When a key is
+    specified for an element of the array, it will be used as the friendly name of the attribute
+    in the generated metadata.
+
 :   *Note*: This list will only be added to the metadata if the `name`-option is also specified.
 
 `attributes.NameFormat`
@@ -411,13 +415,16 @@ Here we will list some examples for this authentication source.
 
     'example-attributes => array(
         'saml:SP',
-        'name' => array( //Name required for AttributeConsumingService-element.
+        'name' => array( // Name required for AttributeConsumingService-element.
             'en' => 'Example service',
             'no' => 'Eksempeltjeneste',
         ),
         'attributes' => array(
             'eduPersonPrincipalName',
             'mail',
+            // Specify friendly names for these attributes:
+            'sn' => 'urn:oid:2.5.4.4',
+            'givenName' => 'urn:oid:2.5.4.42',
         )
         'attributes.required' => array (
             'eduPersonPrincipalName',