Add TUYA_SUPPORT (#1997)

- add experimental `relayDummy` to configure dummy relays at runtime
- add tuya-generic-dimmer #1729
- cleanup broker interface to allow Tuya module to properly receive events, modify broker methods to allow different function signatures
- add basic tests for Tuya frame and data protocol

code/test/lib/StreamString/StreamString.cpp

@@ -0,0 +1,60 @@
+/**
+ StreamString.cpp
+
+ Copyright (c) 2015 Markus Sattler. All rights reserved.
+ This file is part of the esp8266 core for Arduino environment.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+ */
+
+#include <Arduino.h>
+#include "StreamString.h"
+
+size_t StreamString::write(const uint8_t *data, size_t size) {
+    if (!size || !data) return 0;
+    copy((const char*)data, size + 1);
+    return size;
+}
+
+size_t StreamString::write(uint8_t data) {
+    return concat((char) data);
+}
+
+int StreamString::available() {
+    return length();
+}
+
+int StreamString::read() {
+    if(length()) {
+        char c = charAt(0);
+        remove(0, 1);
+        return c;
+
+    }
+    return -1;
+}
+
+int StreamString::peek() {
+    if(length()) {
+        char c = charAt(0);
+        return c;
+    }
+    return -1;
+}
+
+void StreamString::flush() {
+}
+