New release reminders

[ioannis-vm]

• Add the ability to issue a user info message notifying of a new release and showing the install command.
• When running through the entry point (instead of being imported), a command-line argument should be able to turn this on (defaulting to off) to avoid downstream interference.

[nemaarpit]

Please also keep this repository (or the release tags?) up-to-date with the versions used with PBE or released on pip. Pip has versions 3.3.4 released, but no tag for 3.3.4 is present here.

[zsarnoczay]

That's a valid point, thanks.

We have only been creating releases for the major (3.x) and minor (3.x.y) versions. We did not include patches (3.x.y.z) because they typically only include bugfixes and otherwise have identical functionality to the corresponding minor version.

I do see your point, though, and we can certainly create releases for patches as well here.