Couple of symbols messed up by gnulib

[Michael Goffioul]

Under Win32/MSVC:

dirfns.cc: reference to procstreambase::rpl_close and procstreambase::rpl_open
help.cc: ditto
toplev.cc: ditto
input.cc: reference to
tree_statement_list::accept_used_without_including_sys_socket_h
toplev.cc: ditto
octave.cc: missing reference to octave_procbuf::close
pager.cc: ditto
procstream.cc: ditto
procstream.cc: missing reference to octave_procbuf::open

The missing symbols from octave_procbuf are most probably due
to the fact that it exports the gnulib'ed versions: rpl_close and
rpl_open.

Michael.