Update default configuration

Change the default settings for SSL and modify the tests accordingly.
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 987d59d..81daaee 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -1058,7 +1058,7 @@
  *
  * Comment this macro to disable support for SSL 3.0
  */
-#define MBEDTLS_SSL_PROTO_SSL3
+//#define MBEDTLS_SSL_PROTO_SSL3
 
 /**
  * \def MBEDTLS_SSL_PROTO_TLS1