put env should change the real environment

std/python/_std/Sys.hx

@@ -32,6 +32,7 @@ class Sys {
 	}
 
 	public static function putEnv( s : String, v : String ) : Void {
+		python.lib.Sys.putenv(s, v);
 		environ.set(s, v);
 	}
 

std/python/lib/Os.hx

@@ -33,6 +33,8 @@ extern class Os {
 
 	public static var environ : Dict<String, String>;
 
+	public static function putenv (name:String, value:String):Void;
+
 	public static function chdir (path:String):Void;
 
 	public static function unlink (path:String):Void;
@@ -50,6 +52,7 @@ extern class Os {
 
 	public static function rmdir (path:String):Void;
 
+
 	public static function stat (path:String):Stat;
 
 	public static function fchdir (fd:FileDescriptor):Void;