ncurses 6.0 - patch 20170930

ncurses 6.0 - patch 20170930

+ fix a symbol conflict that made ncurses.c C/c menu not work with
  Solaris xpg4 curses.
+ add refresh() call to dots_mvcur.c, needed to use mvcur() with
  Solaris xpg4 curses after calling newterm().
+ minor fixes for configure script from work on ncurses-examples and
  tin.
+ improve animation in test/xmas.c by adding a time-delay in blinkit().
+ modify several test programs to reflect that ncurses honors existing
  signal handlers in initscr(), while other implementations do not.
+ modify bs.c to make it easier to quit.
+ change ncurses-examples to use attr_t vs chtype to follow X/Open
  documentation more closely since Solaris xpg4-curses uses different
  values for WA_xxx vs A_xxx that rely on attr_t being an unsigned
  short.  Tru64 aka OSF1, HPUX, AIX did as ncurses does, equating the
  two sets.