Delete WinHelp related menu items and dialog buttons

WinHelp (*.hlp) was obsoleted from Windows Vista.
So, when you choose the WinHelp related item of menu,
Windows shows an error. It may confuse you.

This patch deletes the WinHelp related items and buttons,
and prevents its confusion.

If you build in the gub environment, please correct a specs file as follows.

```
--- gub/specs/lilypad.py.org    2014-09-15 02:16:39 +0900
+++ gub/specs/lilypad.py        2014-09-15 02:18:21 +0900
@@ -4,8 +4,6 @@
 class LilyPad (target.AutoBuild):
     source = 'http://lilypond.org/download/gub-sources/lilypad/lilypad-0.1.0.0-src.tar.bz2'
     destdir_install_broken = True
-    # FIXME: -DUNICODE is broken, notably for opening files.
-    make_flags = ' CPPFLAGS=-UUNICODE'
     license_files = ['']

 Lilypad = LilyPad

```

I believe that the file open bug of "-DUNICODE" is fixed by d9cbd31ba18805c38584790fa75ff0da3d4e9345 .