Build the help HTML using the shared resources.

def build_help_html():
    """Build the help HTML using the shared resources."""
    remove_from_help = ["not-in-help", "copyright"]
    if sys.platform in ["win32", "cygwin"]:
        remove_from_help.extend(["osx", "linux"])
    elif sys.platform == "darwin":
        remove_from_help.extend(["linux", "windows", "linux-windows"])
    else:
        remove_from_help.extend(["osx", "windows"])
    readme_part_gen = all_but_blocks(remove_from_help, README, newline=None)
    rst_body = "\n".join(list(readme_part_gen) + CHANGES)
    doctree = docutils.core.publish_doctree(rst_body)
    visitor = Doctree2HtmlForWx(doctree)
    doctree.walkabout(visitor) # Fills visitor.body and visitor.toc
    return ( # wx.html.HtmlWindow only renders a HTML subset
      u'<body bgcolor="{bg}" text="{fg}" link="{link}">'
      u'<a name="0"><h1>{title}</h1></a>'
      u"{sectionless}"
      u"{toc}"
      u"<p>This help was generated using selected information from the\n"
      u"Dose <tt>README.rst</tt> and <tt>CHANGES.rst</tt> project files.</p>"
      u'<p><a href="{url}">{url}</a></p><hr/>'
      u"{body}</body>"
    ).format(bg=HELP_BG_COLOR, fg=HELP_FG_COLOR, link=HELP_LINK_COLOR,
             title=HELP_TITLE, sectionless=u"".join(visitor.sectionless),
             toc=u"".join(visitor.toc), url=__url__,
             body=u"".join(visitor.body))