changes for new tcl/tk:

changes for new tcl/tk:
        * gdbtk.c (mainWindow): Deleted.
        (cleanup_init): Don't destroy main window.
        (gdbtk_init): Main window now created by Tk_Init.

        * configure.in: Most X checks now handled automatically by Tk.
        Use new macros to find Tcl/Tk.
        * aclocal.m4: New version for new Tcl/Tk; from Don Libes.
        * config.in, configure: Regenerated.

        * Makefile.in (TCL, TCL_CFLAGS, TK, TK_CFLAGS, X11_CFLAGS,
        X11_LDFLAGS, X11_LIBS): Changed for new Tcl and Tk.