fp/secd/secd.c: added native functions

For now, native functions are:

1) (list x1 x2 x3...) -> '(x1 x2 x3...)
2) (append (x1 x2 ... xM) (y1 y2 ... yN)) -> '(x1 x2 .. xM y1 y2 .. yN)
3) (copy list) -> list
fp/secd: compiler almost runnable