verbatim input, and fix backwards _POSIX_VDISABLE #ifdefs so that raw()
and cbreak() are called properly in get_verbatim_kbinput()


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@1640 35c25a1d-7b9e-4130-9fde-d3aeb78583b8