Add documentation for the pydoc module; contributed by Ka-Ping Yee.

This closes SF patch #494622.

Doc/lib/libpydoc.tex

+\section{\module{pydoc} ---
+         Documentation generator and online help system}
+
+\declaremodule{standard}{pydoc}
+\modulesynopsis{Documentation generator and online help system.}
+\moduleauthor{Ka-Ping Yee}{ping@lfw.org}
+\sectionauthor{Ka-Ping Yee}{ping@lfw.org}
+
+\versionadded{2.1}
+\index{documentation!generation}
+\index{documentation!online}
+\index{help!online}
+
+The \module{pydoc} module automatically generates documentation from
+Python modules.  The documentation can be presented as pages of text
+on the console, served to a Web browser, or saved to HTML files.
+
+The built-in function \function{help()} invokes the online help system
+in the interactive interpreter, which uses \module{pydoc} to generate
+its documentation as text on the console.  The same text documentation
+can also be viewed from outside the Python interpreter by running
+\program{pydoc} as a script at the operating system's command prompt.
+For example, running
+
+\begin{verbatim}
+pydoc sys
+\end{verbatim}
+
+at a shell prompt will display documentation on the \refmodule{sys}
+module, in a style similar to the manual pages shown by the \UNIX{}
+\program{man} command.  The argument to \program{pydoc} can be the name
+of a function, module, or package, or a dotted reference to a class,
+method, or function within a module or module in a package.  If the
+argument to \program{pydoc} looks like a path (that is, it contains the
+path separator for your operating system, such as a slash in \UNIX),
+and refers to an existing Python source file, then documentation is
+produced for that file.
+
+Specifying a \programopt{-w} flag before the argument will cause HTML
+documentation to be written out to a file in the current directory,
+instead of displaying text on the console.
+
+Specifying a \programopt{-k} flag before the argument will search the
+synopsis lines of all available modules for the keyword given as the
+argument, again in a manner similar to the \UNIX{} \program{man}
+command.  The synopsis line of a module is the first line of its
+documentation string.
+
+You can also use \program{pydoc} to start an HTTP server on the local
+machine that will serve documentation to visiting Web browsers.
+\program{pydoc} \programopt{-p 1234} will start a HTTP server on port
+1234, allowing you to browse the documentation at
+\code{http://localhost:1234/} in your preferred Web browser.
+\program{pydoc} \programopt{-g} will start the server and additionally
+bring up a small \refmodule{Tkinter}-based graphical interface to help
+you search for documentation pages.
+
+When \program{pydoc} generates documentation, it uses the current
+environment and path to locate modules.  Thus, invoking
+\program{pydoc} \programopt{spam} documents precisely the version of
+the module you would get if you started the Python interpreter and
+typed \samp{import spam}.