Test suite for all supported checksec file and process hardening checks

[petervas]

This pull request adds a test suite for all supported file and process hardening checks. To generate the test binaries from scratch call build_binaries.sh. The binaries have already been pre-built for this pull request. This test suite should prevent commits that break any of the supported hardening detections.

While generating the test suite the acceptance of process names with numbers has been added to checksec. A minor shellcheck issue has been fixed as well.

[petervas]

Ok so this is working now and only missing the NX Fix from #212.

I'll just merge #212 into this pull request and we'll finally have the basic checksec functionality restored once again. And this test suite should make it a lot harder to break checksec in the future.

[petervas]

What a rough ride. Pull request is ready.

Summary of the changes:

• Add a test suite for all supported file and process hardening checks so new commits do not break the checks anymore.
• Hardening test suite runs in the Ubuntu Docker container. The Photon Container will not run the test suite, because it does not support 32-bit binaries.
• When passing process names they can now include numbers.
• Fix Dockerfile.photon issue that was breaking all commit checks.
• Fix NX detection that was broken by commit https://github.com/slimm609/checksec.sh/commit/3e5a022dccd4531ae8502022ec9737566acaf790 (See Issue https://github.com/slimm609/checksec.sh/issues/209).
• Minor code cleanups and fixes.