Give ConfigParser the capability to set as well as read options, and to write
a representation of the configuration state in .ini format that can be read
back in by a future read() call.  Thus this class is now a back end
for .ini editors as well as parsers.

This patch is complete and tested, but exposes a bug in the ConfigParser
implementation which I have not yet fixed.  Because case information is
discarded during parsing, the output of write() has its case smashed.

I wrote this for a SourceForge interface script called forgetool.
Documentation for the new entry points included.
diff --git a/Doc/lib/libcfgparser.tex b/Doc/lib/libcfgparser.tex
index 2f3536b..32851f5 100644
--- a/Doc/lib/libcfgparser.tex
+++ b/Doc/lib/libcfgparser.tex
@@ -5,6 +5,7 @@
 \modulesynopsis{Configuration file parser.}
 \moduleauthor{Ken Manheimer}{klm@digicool.com}
 \moduleauthor{Barry Warsaw}{bwarsaw@python.org}
+\moduleauthor{Eric S. Raymond}{esr@thyrsus.com}
 \sectionauthor{Christopher G. Petrilli}{petrilli@amber.org}
 
 This module defines the class \class{ConfigParser}.
@@ -113,6 +114,11 @@
 Returns a list of options available in the specified \var{section}.
 \end{methoddesc}
 
+\begin{methoddesc}{has_option}{section, option}
+If the given section exists, and contains the given option. return 1;
+otherwise return 0. (New in 1.6)
+\end{methoddesc}
+
 \begin{methoddesc}{read}{filenames}
 Read and parse a list of filenames.  If \var{filenames} is a string or
 Unicode string, it is treated as a single filename.
@@ -148,3 +154,14 @@
 for the option are \samp{0} and \samp{1}, any others will raise
 \exception{ValueError}.
 \end{methoddesc}
+
+\begin{methoddesc}{set}{section, option, value}
+If the given section exists, set the given option to the specified value;
+otherwise raise \exception{NoSectionError}. (New in 1.6)
+\end{methoddesc}
+
+\begin{methoddesc}{write}{fileobect}
+Write a representation of the configuration to the specified file
+object.  This representation can be parsed by a future \method{read()}
+call. (New in 1.6)
+\end{methoddesc}