Update release notes

Author: fredericDelaporte

releasenotes.txt

@@ -3,7 +3,7 @@
 
 Release notes - NHibernate - Version 5.3.0
 
-206 issues were resolved in this release.
+210 issues were resolved in this release.
 
     ##### Possible Breaking Changes #####
         * A distributed cache may hold conflicting timestamps after upgrade for as much as twelve hours.
@@ -113,6 +113,7 @@ Release notes - NHibernate - Version 5.3.0
    * #2327 Add cross join support for Hql and Linq query provider
    * #2313 Add overloads to ISession.Get taking both an entityName and a lockMode
    * #2294 Add StackExchangeRedis cache provider documentation
+   * #2259 Schema auto-update should throw errors
    * #2221 Support MemberInit expression in group by
    * #2216 Add a driver to support Microsoft.Data.SqlClient provider
    * #2209 IN clause support in hql for composite keys on databases without row value constructor support
@@ -137,6 +138,9 @@ Release notes - NHibernate - Version 5.3.0
 
 ** Improvement
 
+   * #2404 Allow overriding default CastFunction
+   * #2401 Optimize JoinWalker.WhereString method
+   * #2399 Optimize PersistentGenericBag.EqualsSnapshot
    * #2394 Optimize PersistentGenericSet snapshot
    * #2352 Improve performance of ReflectHelper.GetMethod/Definition
    * #2350 Optimize LINQ batch item processing for queries with overridden result type