gmt.c: add classic option to --new-script

[anbj]

I've added the option --new-script-classic to gmt to make a script template without the modern mode related output.
You know, for the old-timers.

This was just an experiment to play with C. Consider to merge. I wont be sad if you choose not to.

[joa-quim]

Please, do not change the formatting. Those tabs above should not be there. Only spaces guarantee a good alignment in all editor settings (and possible terminals)

[anbj]

I'm very certain I used spaces when I made the changes, and double checked now. Do they appear as tabs to you?

[PaulWessel]

Hi @anbj, while it may not be used a lot I am OK with accepting your contribution. However, I'd like to see a few changes:

1. Split the new-script usage message into two separate lines, one for classic and the original one, as is done for other classic versions of options.
2. Use less spaces: Only 1 after the longest of all entries, which after splitting into two lines will remain the show-modules-core I think. As per Improve usage documentation and break synopsis lines for all GMT modules #5341, we want to keep things tighter.
3. You need to add an entry in the gmt.rst file as well for documentation.

[joa-quim]

I don't know how to load your branch without doing a fork of your fork but when I see this displayed by github it normally means tabs

[anbj]

You can check out a PR branch with:

git fetch origin pull/<ID>/head:<BRANCHNAME>
git checkout BRANCHNAME

So in this case it would be:

git fetch origin pull/5403/head:add-classic-script-template
git checkout add-classic-script-template

But again, I typed space when I did this, so it should be good.

[joa-quim]

OK, thanks. No big deal either (and easy to fix in case they were there). But can't look more at this now. Need to go out.

[joa-quim]

Regarding the PR, I have no particular opinion. Asking classic prints this

gmt --new-script-classic
@echo off
REM Date:    2021-06-28T20:48:53
REM User:    j
REM Purpose: Purpose of this script

which does not seem a particular useful bit of info.

[anbj]

I'm closing this. It was fun to do, but with 1-2 people using it, it's not worth the code change.

[PaulWessel]

Sorry we could not be more welcoming on this one... But see #5341 if you want to practice more C!

[anbj]

No worries! I'll check out #5341!