Updated the changelog and upgrade notes.

docs/simplesamlphp-changelog.md

@@ -15,13 +15,13 @@ Released TBD
   * Added new `AttributeValueMap` authproc filter.
   * Added attributemaps for OIDs from SIS (Swedish Standards Institute) and
     for eduPersonUniqueId, eduPersonOrcid and sshPublicKey.
-  * Added option to specify metadata signing and digest algorithm
+  * Added an option to specify metadata signing and digest algorithm
     `metadata.sign.algorithm`.
-  * Added option for regular expression matching of trusted.url.domains via new
+  * Added an option for regular expression matching of trusted.url.domains via new
     `trusted.url.regex` setting.
   * The `debug` option is more finegrained and allows one to specify whether
     to log full SAML messages, backtraces or schema validations separately.
-  * Added a check for the latest simpleSAMLphp version on the front page.
+  * Added a check for the latest SimpleSAMLphp version on the front page.
     It can be disabled via the new setting `admin.checkforupdates`.
   * Added a warning when there's a probable misconfiguration of PHP sessions.
   * Added ability to define additional attributes on ContactPerson elements

docs/simplesamlphp-upgrade-notes-1.15.md

 Upgrade notes for SimpleSAMLphp 1.15
 ====================================
 
-Minimum required PHP version is 5.4. Dependency on mcrypt has been dropped.
+The minimum required PHP version is now 5.4. The dependency on mcrypt has been
+dropped.
 
 A new templating system based on Twig has been introduced. The old templating
 system is still available but should be considered deprecated.
 
+A new internationalization system based on Gettext has been introduced. While
+old templates can use either the old or the new system (refer to the
+"language.i18n.backend" configuration option for more information on how to
+choose the internationalization backend), new Twig templates can only use the
+new Gettext internationalization system.
+
 The integrated _Auth Memcookie_ support is now deprecated and will no longer
 be available starting in SimpleSAMLphp 2.0. Please use the new
 [memcookie module](https://github.com/simplesamlphp/simplesamlphp-module-memcookie)