doc: updated changelog and credits.

doc/changelog.dox

@@ -217,6 +217,10 @@ See also:
     option available since Emscripten 1.38.27 and with older versions
 -   @ref Platform::WindowlessEglApplication was adapted to properly create
     WebGL 2 contexts both in Emscripten 1.38.24 and in older versions
+-   @ref Platform::Sdl2Application::exit() and
+    @ref Platform::GlfwApplication::exit() now have an optional parameter to
+    specify the actual application return code (see
+    [mosra/magnum#332](https://github.com/mosra/magnum/pull/332))
 
 @subsubsection changelog-latest-changes-text Text library
 

doc/credits.dox

@@ -114,7 +114,8 @@ Are the below lists missing your name or something's wrong?
 -   **Guillaume Giraud** ([\@Guillaume227](https://github.com/Guillaume227)) ---
     algorithm bugfixes
 -   **Guillaume Jacquemin** ([\@williamjcm](https://github.com/williamjcm)) ---
-    MSYS2 packages, additions to @ref Platform::Sdl2Application
+    MSYS2 packages, additions to @ref Platform::Sdl2Application and
+    @ref Platform::GlfwApplication
 -   **Hilario Pérez Corona** ([\@hpcorona](https://github.com/hpcorona)) ---
     improvements to @cb{.cmake} android_create_apk() @ce
 -   **Ivan P.** ([\@uzername](https://github.com/uzername)) --- documentation