termstr: Termstrs can be constructed from strings containing tabs.

- The tab expansion happens after the padding so that the tab stops
  are correctly aligned even with wide chars.

termstr/termstr.py

@@ -181,7 +181,7 @@ class TermStr(collections.UserString):
             try:
                 self.data, self.style = data.data, data.style
             except AttributeError:
-                self.data = _pad_wide_chars(data)
+                self.data = _pad_wide_chars(data).expandtabs()
                 self.style = (style,) * len(self.data)
 
     @classmethod