[OSM-dev] New osmlib-base (after nearly 3 years)

[Serge Wroclawski]

Hi all,

As is so often the case with software in our community, we add
features to scratch our own itch.

Jochen has largely moved away from osmlib to work on osmium, so the
software hasn't had any updates in nearly 3 years.

In that spirit, I've taken osmlib-base and forked it. My version is
at: https://github.com/emacsen/osmlib-base

I've added a few features:

* osmlib now parses and supports the visible flag.
* osmlib now emits the visible flag
* osmlib can now parse OSMChange XML through the new OSM::Change class
* osmlib now can parse generic OSM Actions (create/modify/delete)
through the new OSM::Action class

All the new features have unit tests around them and the Change and
Action features are documented in the README.

I'm not sure about the future of this library, whether there's
interest in it by others, but this software it out, and usable by
others, if you want to use it.

- Serge