Add GitHub actions for CI and release

[ThePrez]

PR is a mere suggestion as an alternative to Jenkins-based builds. I have no assertion that this PR should or need to land, but could be an interesting discussion

[kadler]

This is way more complicated than the Jenkins build, though the Jenkins build is more complicated on the backend (ie you need Jenkins set up).

[ThePrez]

This is way more complicated than the Jenkins build, though the Jenkins build is more complicated on the backend (ie you need Jenkins set up).

I agree. Though one benefit of the GH actions approach is that it can build a release and publish it to the GitHub release. Jenkins can probably do that too (and I am not sure how much utility there is, given it still ultimately ends up in a PTF)

[ThePrez]

Really should have folded #50 into these, since I also made a make target for a save file but in a much more rudimentary capacity

[kadler]

I agree. Though one benefit of the GH actions approach is that it can build a release and publish it to the GitHub release. Jenkins can probably do that too (and I am not sure how much utility there is, given it still ultimately ends up in a PTF)

I believe I have some code to do that IIRC. Got sidetracked testing with various compression tools to compress the save files since they are so big.

[kadler]

Changes here: https://github.com/IBM/xmlservice/compare/create-release?expand=1

Creates 3 XZ-compressed save files:

• xmlservice.savf.xz: includes just the programs and service programs for XMLSERVICE
• xmlservice-tests.savf.xz includes just the tests, making it easy to run various itoolkit tests
• xmlservice-full.savf.xz: includes everything

Example release built by the branch: https://github.com/IBM/xmlservice/releases/tag/test-tag