Fixed 2 FIXMEs in nano.c:

Fixed 2 FIXMEs in nano.c:
do_enter: the reset_cursor was needed. code cleaned up a bit with a comment
          explaining the situation there.
do_justify: the second edit_refresh exposed a bug in how we were updateing
            editbot when we needed to rebuild it.  This functionality has
            been moved into winio.c:fix_editbot, and all places that were
            doing so that I could find have been updated. (files.c:
            do_insertfile, nano.c: handle_sigwinch and do_justify)

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@64 35c25a1d-7b9e-4130-9fde-d3aeb78583b8