style question as by commit dbcfe3eb6 / Aid Vim editor

Hello Brandon

I read your commit dbcfe3eb6 / Aid Vim editor which provides `src/devices/xditview/xditview` the instruction

```
vim:set cindent noexpandtab shiftwidth=4 softtabstop=4 textwidth=72:
```

This is in contrast to `/contrib/chem/chem.pl` with the line

```
# vim: set cindent noexpandtab shiftwidth=2 softtabstop=2 textwidth=72:
```

Do you think the former pattern (including `4` on `shiftwidth` and `softtabstop`) were equally useful here, for consistency of style?

In addition, `chem`'s example files recently edited (`contrib/chem/examples` excluding the ones of sub folder `cstr-122`) sometimes have the note of `textwidth=72` as one (and only) guideline for vim, sometimes they do not.  Would you prefer that these equally include the complete line (with both `shiftwidth` and `softtabstop` set to `4`) -- again for consistency, or with `textwidth=72` only, or be without such an indication at all?  The later pattern is seen for instance on each example file in `contrib/chem/examples/cstr-122` except for `ch2a_ethyl.chem`, ch4a_stick.chem`, and `ch4j_ring4.chem`).

Regards,
Norwid