Look for ncurses/curses.h before curses.h

Solaris puts the ncurses header in /usr/include/ncurses, and we need
that to compile with -Werror.

Fixes: #889

bin/varnishstat/varnishstat_curses.c

@@ -34,7 +34,11 @@
 
 #include <sys/time.h>
 
+#ifdef HAVE_NCURSES_CURSES_H
+#include <ncurses/curses.h>
+#elif HAVE_CURSES_H
 #include <curses.h>
+#endif
 #include <errno.h>
 #include <signal.h>
 #include <stdio.h>

configure.ac

@@ -87,6 +87,7 @@ AC_SUBST(CURSES_LIBS)
 if test "$have_curses" = no; then
 	AC_MSG_WARN([curses not found; some tools will not be built])
 fi
+AC_CHECK_HEADERS([ncurses/curses.h curses.h])
 AM_CONDITIONAL([HAVE_CURSES], [test x$have_curses = xyes])
 
 save_LIBS="${LIBS}"