Several changes made to fts.c in Gnulib

[Paul Eggert]

I found some subtle bugs in Gnulib fts.c, and created a test case that reliably 
fails in reiserfs due to confusion with st_nlink. I added this test case to 
Gnulib and fixed the bugs I found. As far as I can see, the only problems that 
should affect findutils and coreutils are minor performance problems. However, I 
thought I'd send out some email as a heads-up, because the code is reasonably 
subtle and I may have introduced some bugs.

Here are the patches I installed:
http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=b7363b496caf60600eefa0a5f2d37f77a5dee606

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=9c7ef4eef9540a0a762c4781d7ed5a1b8623e59b

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=f7eb1b99e30517fc50c130cdecec24059a1b7c4f

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=2649851d0409c3fafee7cf396d11c10892ac0e53

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=b446700e06b71f8170c46371261e8334888df7f8

http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=e66b0b94e7239fb47c9ccc2c704bb1149164d6ed