Bug in acepack (PR#2352)

This ancient bug was tracked to  the acepack library, line 556 in line
src/avas.f

 The troublesome line is:
	if (x(n).gt.x(1)) go to 30

 Since the input arguments are  empty, referencing x(1) and x(n) cause
a  Segmentation fault,  and  cause  R to  crash.   Acepack author  and
maintainer Rob Tibshirani <tibs at utstat.toronto.edu> has been contacted
with this  information.  This is not  a bug with R,  but with acepack,
and should be closed.

Neha Pandey <neha.pandey at gmail.com>
Vikram Aggarwal <vikram at mayin.org>

Vikram Aggarwal: http://www.mayin.org/~aragorn/