support mysql procedure declare exception handler

src/main/java/com/alibaba/druid/sql/parser/Token.java

@@ -138,6 +138,13 @@ public enum Token {
     CLOSE("CLOSE"),
     OUT("OUT"),
     INOUT("INOUT"),
+    HANDLER("HANDLER"),
+    EXIT("EXIT"),
+    UNDO("UNDO"),
+    SQLSTATE("SQLSTATE"),
+    SQLWARNING("SQLWARNING"),
+    SQLEXCEPTION("SQLEXCEPTION"),
+    FOUND("FOUND"),
     
     //postgresql
     WINDOW("WINDOW"),