- Upstream code includes only upto emacs 24 (?)
  .. it is kind of beyond packaging 
  .. and may ignore for the moment.
  
- Which tc-is??.el is byte-compiled depends on emacs version
  (incremental search needs by-version caring).
  So fix PLIST variation on emacsen 20/21/22/23/24
  .. meaning that working emacs version detection is necessary.