doc: updated credits and changelog.

doc/changelog.dox

@@ -429,6 +429,9 @@ See also:
     information.
 -   Suppressing a CMake policy-related warning if the global `CMAKE_AUTOMOC` is
     set on CMake 3.10+ (see [mosra/magnum#504](https://github.com/mosra/magnum/pull/504))
+-   Updated Debian build instructions to pass `--no-sign` to
+    `dpkg-buildpackage`, avoiding a confusing error message that might lead
+    people to think the packaging failed (see [mosra/magnum-plugins#105](https://github.com/mosra/magnum-plugins/issues/105))
 
 @subsection changelog-latest-bugfixes Bug fixes
 

doc/credits.dox

@@ -137,6 +137,8 @@ Are the below lists missing your name or something's wrong?
     MSYS2 packages, additions to @ref Audio, @ref Platform::Sdl2Application and
     @ref Platform::GlfwApplication, [base-wxwidgets](https://github.com/mosra/magnum-bootstrap/tree/base-wxwidgets)
     bootstrap project
+-   **Hans Loeblich** ([\@thehans](https://github.com/thehans)) ---
+    improvements to Debian package building experience
 -   **Hilario Pérez Corona** ([\@hpcorona](https://github.com/hpcorona)) ---
     improvements to @cb{.cmake} android_create_apk() @ce
 -   **Ivan P.** ([\@uzername](https://github.com/uzername)) --- documentation