The upgrade script misses the altering of spoint operator family
to add operator 17. It is required for k-NN search.

Change the version to 1.5.1.

Add TOK_ prefix to INT, FLOAT, SIGN token names to distinguist these
names from macro directives under mingw64.

This is so we do not invent values for pm, parallax, or rv.  We
are actually a bit over-cautious and invalidate both PMs even if
only one is missing.  This is because PMs mix, and hence there are traces
of the invented 0 in the other component of the PM.  Similarly,
when the parallax is missing or bad, the RV would be heavily contaminated;
in these cases, we copy through the original RV, as it may still be useful
and certainly will not be grossly wrong.

(sorry about a few whitespace diffs introduced by killing trailing whitespace
in sql/epochprop.sql and src/epochprop.c)

This merge request addresses issue #125 by updating the GitHub Actions CI workflow to build and test on PostrgeSQL 17.

This PR updates the version number on `actions/upload-artifact` in `.github/workflows/build-and-check.yml` in order to silence the following warning:

> The following actions use a deprecated Node.js version and will be forced to run on node20: actions/upload-artifact@v3. For more info: https://github.blog/changelog/2024-03-07-github-actions-all-actions-will-run-on-node20-instead-of-node16-by-default/

https://github.com/actions/upload-artifact says:

> actions/upload-artifact@v3 is scheduled for deprecation on November 30, 2024. [Learn more.](https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/) Similarly, v1/v2 are scheduled for deprecation on June 30, 2024. Please update your workflow to use v4 of the artifact actions. This deprecation will not impact any existing versions of GitHub Enterprise Server being used by customers.