[tz] Proposal: Use Git and Github better

[Paul Eggert]

Dirkjan Ochtman wrote:
> I know some projects have their pull request stuff sent to the mailing
> list email, so it might be possible to use pull requests this way and
> still be able to follow discussion via the mailing list.

I don't encourage pull requests on Github, as the mailing list is the 
primary way of discussing proposed changes.  On the few occasions where 
people have made pull requests anyway, I've tried to migrate discussion 
of the nontrivial changes to the mailing list.

Nowadays it's a bit more convenient for me if emailed patches are 
generated via "git format-patch" or "git send-email" but this is not 
required.  More generally, I'd rather not formally require a lot of Git- 
or Github-specific features in tz maintenance.  There are advantages to 
having multiple branches, pull requests, etc., but there are also 
disadvantages and it's not clear that the benefits would outweigh the 
costs.  Although Github is a convenient repository, other repositories 
are also convenient and Github itself may be superseded some day.  And 
although I prefer Git, the next maintainer may prefer something else. 
As long as we can talk about changes via patches, pretty much any 
version-control system will do.

Finally, I'd rather keep the experimental repository informal.  It's 
just my personal list of changes that I'm thinking of putting into the 
next release.  It's intended to be releasable at any time (though a 
release is usually not urgent and we like to put things off :-). 
Obviously I'll make mistakes sometimes, just as releases themselves 
sometimes contain mistakes.  But these can be fixed.