bug#41744: 27.0.91; Various D-Bus cleanups

[Basil L. Contovounesios]

X-Debbugs-Cc: Michael Albinus <michael.albinus@gmx.de>
Severity: minor
Tags: patch

While reading through the D-Bus manual and implementation, I noticed
some opportunities for small cleanups.

I propose these documentation cleanups for emacs-27:

0001-Clean-up-D-Bus-documentation.patch
Description: Text Data

And these implementation cleanups for master:

0001-Various-dbus.el-cleanups.patch
Description: Text Data

Are these changes acceptable?  WDYT?

Thanks,

-- 
Basil

In GNU Emacs 27.0.91 (build 12, x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll 
bars)
 of 2020-06-06 built on thunk
Repository revision: c1f4c0bc839324d2049ae45a74381684a5727f60
Repository branch: blc/27/dbus
Windowing system distributor 'The X.Org Foundation', version 11.0.12008000
System Description: Debian GNU/Linux bullseye/sid

Configured using:
 'configure 'CC=ccache gcc' 'CFLAGS=-O0 -g3 -ggdb -gdwarf-4'
 --config-cache --prefix=/home/blc/.local --program-suffix=27
 --enable-checking=yes,glyphs --enable-check-lisp-object-type
 --with-x-toolkit=lucid --with-file-notification=yes --with-x'

Configured features:
XAW3D XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY
INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF
XFT ZLIB TOOLKIT_SCROLL_BARS LUCID X11 XDBE XIM MODULES THREADS
LIBSYSTEMD JSON PDUMPER LCMS2 GMP