clang64 compiler warnings

[GitMensch]

cc: warning: -O4 is equivalent to -O3 [-Wdeprecated]

In file included from ../pdcurses/color.c:3:
In file included from ../curspriv.h:12:
../curses.h:1802:63: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
PDCEX void    PDC_set_window_resized_callback(void (*callback)());
                                                              ^
                                                               void
../pdcurses/getch.c:427:19: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
long PDC_millisecs( )
                  ^
                    void

[Bill-Gray]

Seems to be fixed with the three commits referenced above.