Add path expansion to fs.

vispa/remote/filesystem.py

@@ -336,6 +336,8 @@ class FileSystem(object):
         # return
         return self.handle_file_name_collision(newname, path)
 
+    def expand(self, path):
+        return os.path.expanduser(os.path.expandvars(path))
 
 def string_compare(a, b):
     if a == b: