Code Cleanup

- Removed code that creates the ~/.task/extensions directory, which will not be
  needed until 2.1.  Until then, it is clutter.

src/Context.cpp

@@ -504,8 +504,10 @@ void Context::createDefaultConfig ()
   config.createDefaultData (data_dir);
 
   // Create extension directory, if necessary.
+/* TODO Enable this when the time is right, say for 2.1
   if (! extension_dir.exists ())
     extension_dir.create ();
+*/
 }
 
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