Remove Palm OS port.

The platform targeted by this port doesn't exist any more and the port never
achieved really working state so remove the code to avoid having to maintain
it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70345 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/strconv.h

@@ -25,9 +25,7 @@
 #  undef __BSEXCPT__
 #endif
 
-#ifndef __WXPALMOS5__
 #include <stdlib.h>
-#endif // ! __WXPALMOS5__
 
 class WXDLLIMPEXP_FWD_BASE wxString;