Document maintenance of idlelib/help.html in idlelib.

Lib/idlelib/help.py

@@ -45,6 +45,8 @@ class HelpParser(HTMLParser):
     The overridden handle_xyz methods handle a subset of html tags.
     The supplied text should have the needed tag configurations.
     The behavior for unsupported tags, such as table, is undefined.
+    If the tags generated by Sphinx change, this class, especially
+    the handle_starttag and handle_endtags methods, might have to also.
     """
     def __init__(self, text):
         HTMLParser.__init__(self, convert_charrefs=True)
@@ -226,7 +228,28 @@ class HelpWindow(Toplevel):
 
 
 def copy_strip():
-    "Copy idle.html to idlelib/help.html, stripping trailing whitespace."
+    """Copy idle.html to idlelib/help.html, stripping trailing whitespace.
+    
+    Files with trailing whitespace cannot be pushed to the hg cpython
+    repository.  For 3.x (on Windows), help.html is generated, after
+    editing idle.rst in the earliest maintenance version, with
+      sphinx-build -bhtml . build/html
+      python_d.exe -c "from idlelib.help import copy_strip; copy_strip()"
+    After refreshing TortoiseHG workshop to generate a diff,
+    check  both the diff and displayed text.  Push the diff along with
+    the idle.rst change and merge both into default (or an intermediate
+    maintenance version).
+    
+    When the 'earlist' version gets its final maintenance release,
+    do an update as described above, without editing idle.rst, to
+    rebase help.html on the next version of idle.rst.  Do not worry
+    about version changes as version is not displayed.  Examine other
+    changes and the result of Help -> IDLE Help.
+    
+    If maintenance and default versions of idle.rst diverge, and
+    merging does not go smoothly, then consider generating
+    separate help.html files from separate idle.htmls.
+    """
     src = join(abspath(dirname(dirname(dirname(__file__)))),
                'Doc', 'build', 'html', 'library', 'idle.html')
     dst = join(abspath(dirname(__file__)), 'help.html')