Update UPGRADING.md

UPGRADING.md

@@ -1,11 +1,38 @@
 # UPGRADE NOTES
 
-## 3.3 to 4.0 
+## 3.4 to 4.0 
 
 **Assertion processor BC breaking change**
 
 The response processor in pre 4.0 releases assumed all assertions are decrypted, and caused a fatal error when the response was unsigned.
 This problem was fixed in [#120](https://github.com/simplesamlphp/saml2/pull/120). 
 
 If you are using the assertion processor as a stand-alone component, then you will have to update your code to reflect this
-change, see: [e6c01fa](https://github.com/simplesamlphp/saml2/commit/e6c01fa9b0e815682e24916f03a84d245480c4a0).
+change, see: [e6c01fa](https://github.com/simplesamlphp/saml2/commit/e6c01fa9b0e815682e24916f03a84d245480c4a0).
+
+**NameID's and Issuers**
+
+In pre 4.0 releases we allowed both objects and arrays to be used for Issuers and nameID's. We know only support objects.
+If in your code you use something like this:
+
+``
+$assertion = new \SAML2\Assertion();
+$assertion->setIssuer('someissuer');
+``
+
+You would now replace that with:
+
+``
+$issuer = new \SAML2\XML\saml\Issuer();
+$issuer->setValue('someissuer');
+
+$assertion = new \SAML2\Assertion();
+$assertion->setIssuer($issuer);
+``
+
+**Class properties**
+All public properies have been replaced by either protected or private properties.
+Public getter/setter methods are available to set/get values.
+
+**Autoloading classes**
+The PSR-0 autoloader has been removed. If your code isn't prepared to use PSR-4 namespaces yet, then you would have to change that before using this version.