ncurses 5.8 - patch 20110329

> portability fixes for Ada95 binding:
+ add configure check to ensure that SIGINT works with gnat.  This is
  needed for the "rain" sample program.  If SIGINT does not work, omit
  that sample program.
+ correct typo in check of $PKG_CONFIG variable in Ada95/configure
+ add ncurses_compat.c, to supply functions used in the Ada95 binding
  which were added in 5.7 and later.
+ modify sed expression in CF_NCURSES_ADDON to eliminate a dependency
  upon GNU sed.