fuse.py: Window.__iadd__, aggregating windows without extending lists.

Window.__add__ extends the lists, it is not wanted when one simply wants to combine windows.
This .__iadd__ method is actually dead code, but the method is nice.

server/fuse.py

@@ -65,7 +65,19 @@ class Window:
         
         
     ### 
+
+    def __iadd__(self, other):
+        ### Not used now
+        """Add other.size to self.size in-place, without extending lists"""
+
+        assert(len(self.d['size']) == len(other.d['size']))
+        self.d['size'] = [my + her for (my, her) in zip(self.d['size'], other.d['size'])]
+
+        return self
+        
     def __add__(self, other):
+        """Concat two windows, extending lists such as 'size'"""
+
         #data we don't need to duplicate
         myList = [ "V", "D", "J", "Vend", "Dend", "Jstart", "Dstart", "top", "window", "Nlength", "sequence", "name", "id", "status"]
         obj = Window(1)