bring description of optional and keyword args for DictReader and DictWriter

classes into line with the actual code.  I didn't see any obvious examples
of latex formatting for *args and **kwds so I just guessed.

Doc/lib/libcsv.tex

@@ -122,7 +122,7 @@ The \module{csv} module defines the following classes:
                               restkey=\constant{None}\optional{,
 			      restval=\constant{None}\optional{,
                               dialect=\code{'excel'}\optional{,
-			      fmtparam}}}}}}
+			      *args, **kwds}}}}}}
 Create an object which operates like a regular reader but maps the
 information read into a dict whose keys are given by the optional
 {} \var{fieldnames}
@@ -133,15 +133,16 @@ the value of \var{restval} will be used as the default value.  If the row
 read has more fields than the fieldnames sequence, the remaining data is
 added as a sequence keyed by the value of \var{restkey}.  If the row read
 has fewer fields than the fieldnames sequence, the remaining keys take the
-value of the optional \var{restval} parameter.  All other parameters are
-interpreted as for \class{reader} objects.
+value of the optional \var{restval} parameter.  Any other optional or
+keyword arguments are passed to the underlying \class{reader} instance.
 \end{classdesc}
 
 
 \begin{classdesc}{DictWriter}{csvfile, fieldnames\optional{,
                               restval=""\optional{,
                               extrasaction=\code{'raise'}\optional{,
-                              dialect=\code{'excel'}\optional{, fmtparam}}}}}
+                              dialect=\code{'excel'}\optional{,
+			      *args, **kwds}}}}}
 Create an object which operates like a regular writer but maps dictionaries
 onto output rows.  The \var{fieldnames} parameter identifies the order in
 which values in the dictionary passed to the \method{writerow()} method are
@@ -151,8 +152,9 @@ specifies the value to be written if the dictionary is missing a key in
 method contains a key not found in \var{fieldnames}, the optional
 \var{extrasaction} parameter indicates what action to take.  If it is set
 to \code{'raise'} a \exception{ValueError} is raised.  If it is set to
-\code{'ignore'}, extra values in the dictionary are ignored.  All other
-parameters are interpreted as for \class{writer} objects.
+\code{'ignore'}, extra values in the dictionary are ignored.  Any other
+optional or keyword arguments are passed to the underlying \class{writer}
+instance.
 
 Note that unlike the \class{DictReader} class, the \var{fieldnames}
 parameter of the \class{DictWriter} is not optional.  Since Python's