Issue #4550 Avoid "using" directives in included files

[Dan Eble]

Begin forwarded message:
> 
> From: "pkx166h" <address@hidden>
> Subject: [testlilyissues:issues] #4550 Avoid "using" directives in included 
> files
> Date: January 22, 2020 at 10:13:39 EST
> To: "[testlilyissues:issues] " <address@hidden>
> Reply-To: "[testlilyissues:issues] " <address@hidden>
> 
> Patch: new --> review
> Comment:
> Passes make, make check and a full make doc.
> 
If there is someone here willing to spend the personal and machine time to test 
this patch in GUB, it would be very helpful.  The first attempts at this change 
(some years ago) were plagued by issues that didn't show up until after the 
changes were pushed.  I expect that they have been fixed, but it would be nice 
to be sure before pushing.

https://codereview.appspot.com/579240043/
— 
Dan