readline detection fixes by Edward Rudd.

configure.in

@@ -174,13 +174,13 @@ AC_ARG_ENABLE(readline,
               , enable_readline=yes)
 if test x$enable_readline = xyes; then
   AC_CHECK_HEADER(readline/readline.h, have_readline_hdr=yes)
-  AC_CHECK_LIB(readline, readline, have_readline_lib=yes)
+  AC_CHECK_LIB(readline, readline, have_readline_lib=yes, , -lcurses)
   AC_CHECK_HEADER(readline/history.h, have_history_hdr=yes)
-  AC_CHECK_LIB(readline, add_history, have_history_lib=yes)
+  AC_CHECK_LIB(readline, add_history, have_history_lib=yes, , -lcurses)
   if test x$have_readline_hdr = xyes -a x$have_readline_lib = xyes; then
     if test x$have_history_hdr = xyes -a x$have_history_lib = xyes; then
       AC_DEFINE(PHYSFS_HAVE_READLINE)
-      LIBS="$LIBS -lreadline"
+      LIBS="$LIBS -lreadline -lcurses"
     fi
   fi
 fi