Backlog

- Removed backlog file processing, which slows down processing.  When
  2.1 has taskd support, the backlog will be cleared, but until then there
  is no point in accumulating transactions.

src/Context.cpp

@@ -425,8 +425,10 @@ void Context::shadow ()
     if (shadow_file._data == location + "/undo.data")
       throw std::string (STRING_CONTEXT_SHADOW_U);
 
+/*
     if (shadow_file._data == location + "/backlog.data")
       throw std::string (STRING_CONTEXT_SHADOW_B);
+*/
 
     if (shadow_file._data == location + "/synch.key")
       throw std::string (STRING_CONTEXT_SHADOW_S);