Write deprecation warning on non-empty $extensions array passed to V8Js::__construct

tests/extensions_basic.phpt

@@ -36,5 +36,7 @@ array(2) {
     bool(false)
   }
 }
+
+Deprecated: V8Js::__construct(): Use of extensions is deprecated, $extensions array passed in %s%eextensions_basic.php on line 8
 Hello world!
 ===EOF===

tests/extensions_circular_dependency.phpt

@@ -41,6 +41,8 @@ array(2) {
   }
 }
 
+Deprecated: V8Js::__construct(): Use of extensions is deprecated, $extensions array passed in %s%eextensions_circular_dependency.php on line 8
+
 Warning: Fatal V8 error in v8::Context::New(): Circular extension dependency in %s on line 8
 
 Fatal error: Uncaught V8JsException: Failed to create V8 context. Check that registered extensions do not have errors. in %s:8

v8js_class.cc

@@ -401,6 +401,11 @@ static PHP_METHOD(V8Js, __construct)
 	if (exts_arr)
 	{
 		exts_count = zend_hash_num_elements(Z_ARRVAL_P(exts_arr));
+
+		if (exts_count != 0) {
+			php_error_docref(NULL, E_DEPRECATED, "Use of extensions is deprecated, $extensions array passed");
+		}
+
 		if (v8js_create_ext_strarr(&exts, exts_count, Z_ARRVAL_P(exts_arr)) == FAILURE) {
 			zend_throw_exception(php_ce_v8js_exception,
 				"Invalid extensions array passed", 0);