Merge branch 'maint-0.4.1' into maint-0.4.2

changes/bug34078

+  o Minor bugfixes (compiler compatibility):
+    - Avoid compiler warnings from Clang 10 related to the use of
+      GCC-style "/* falls through */" comments.  Both Clang and GCC allow
+      __attribute__((fallthrough)) instead, so that's what we're using now.
+      Fixes bug 34078; bugfix on 0.3.1.3-alpha.