Fix "make distcheck"

[wrp]

The 'distcheck' recipe should work, and it should execute the test suite. This PR adds a wrapper script to invoke testprog and adds all the necessary source files to the distribution tarball so that the distcheck target can run.

This PR stacks on #113. Since all of the autotool meta-data files are included in the repository, the diff appears significant, but this is just few lines in Makefile.am and the addition of the run-test script.

[esabol]

There's already a test for this in https://github.com/HEASARC/cfitsio/blob/develop/.github/workflows/ci.yml, so there's some redundancy here with your run-test script. If this were to be merged, the CI workflow should be modified to use your run-test script.

[esabol]

Thank you for adding the modifications to the ci.yml. 👍

Checks failed, need to re-review

[bryanirby]

Hi @wrp - I'm unable to merge this PR due to failed checks resulting from a missing "check-TESTS" target. It's possible things got mangled during my review and attempted conflict resolution, but I see the same error when running 'make distcheck' on your add-check-target branch. Are you able to comment on this issue? Thanks.

[wrp]

Rebased. 'make distcheck' works for me locally and is passing in the github runners. Looks like the rebase restored the autoreconf changes to Makefile.in

[bryanirby]

I do note that 'make distcheck' seems fragile on some systems. If a UID is greater than 2^21 - 1 (which mine are on our Macs) the configure decides that the UID is "not supported by ustar format", and this then results in a make failure with little information about the cause. Closer inspection reveals that the UID setting causes the am__tar variable (intended for tar, gtar, gnutar) to be "none", which leads to the make distcheck error.