ncurses 5.9 - patch 20111119

+ remove obsolete/conflicting fallback definition for _POSIX_SOURCE
  from curses.priv.h, fixing a regression with IRIX64 and Tru64
  (cf: 20110416)
+ modify _nc_tic_dir() to ensure that its return-value is nonnull,
  i.e., the database iterator was not initialized.  This case is needed
  to when tic is translating to termcap, rather than loading the
  database (cf:  20111001).