do use micro version number in the DLL names -- but in the unstable branch only

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@19305 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

distrib/msw/tmake/lib/wxVersion.pm

@@ -48,6 +48,18 @@ sub GetVersion()
 
     $numGot == 3 or die "Failed to read the version from $filename.\n";
 
+    # release number if used in the DLL file names only for the unstable branch
+    # as for the stable branches the micro releases are supposed to be
+    # backwards compatible and so should have the same name or otherwise it
+    # would be impossible to use them without recompiling the applications
+    # (which is the whole goal of keeping them backwards compatible in the
+    # first place)
+    #
+    # and the final piece of the puzzle: stable branches are those with even
+    # minor version number (and unstable -- with odd)
+    $versions{'MICRO_IF_UNSTABLE'} = $versions{'MINOR'} % 2 ? $versions{'MICRO'}
+                                                            : "";
+
     return %versions;
 }