Add explicit information about task dplot

doc/user/dplot.tex

@@ -14,7 +14,7 @@ from SCF or DFT calculation. The output file is either in
 (default)
  or in the 
 \htmladdnormallink{Gaussian Cube}{http://www.gaussian.com/00000430.htm}  
-format. 
+format.  DPLOT is not executed until the "task dplot" directive is given.  
 Different sub-directives are described below.
 
 \section{GAUSSIAN --- Gaussian Cube format}

doc/user/top-level.tex

@@ -776,6 +776,7 @@ below, with the corresponding entries for string variable \verb+<task>+.
   \item \verb+rtdbprint+ --- Print the contents of the database.
   \item \verb+cphf+ --- Invoke the CPHF module.
   \item \verb+property+ --- Perform miscellaneous property calculations.
+  \item \verb+dplot+ --- Execute a DLOT run (Section \ref{sec:dplot})
 \end{itemize}
 
 This directive also recognizes the keyword \verb+ignore+, which allows