Initial batch of mocks for host side testing

tests/host/common/Arduino.cpp

@@ -0,0 +1,29 @@
+//
+//  Arduino.cpp
+//  esp8266-host-tests
+//
+//  Created by Ivan Grokhotkov on 02/03/16.
+//  Copyright © 2016 esp8266.com. All rights reserved.
+//
+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>
+#include <sys/time.h>
+#include "Arduino.h"
+
+
+extern "C" unsigned long millis()
+{
+    timeval time;
+    gettimeofday(&time, NULL);
+    return (time.tv_sec * 1000) + (time.tv_usec / 1000);
+}
+
+
+extern "C" void yield()
+{
+}
+
+
+extern "C" void __panic_func(const char* file, int line, const char* func) {
+    abort();
+}