Use correct extensions in wxDynamicLibrary::CanonicalizeName() on OS X.

Contrary to the documentation, this function incorrectly appended the
.bundle extension on OS X for libraries as well as modules.

Fixed to use .dylib for libraries (wxDL_LIBRARY) and continue to use
.bundle for loadable modules (wxDL_MODULE). Change GetDllExt() to take optional wxDynamicLibearyCategory argument.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74161 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/dlmsw.cpp

@@ -29,8 +29,6 @@
 #include "wx/msw/debughlp.h"
 #include "wx/filename.h"
 
-const wxString wxDynamicLibrary::ms_dllext(wxT(".dll"));
-
 // ----------------------------------------------------------------------------
 // private classes
 // ----------------------------------------------------------------------------