* Updates to tests including whitespace scrub test
* Adding oXygen project
* Integration work on specs and unit tests / XSLT and Schematron
* Profile resolution testing infrastructure, plus some tests
* Some test files with expected results
* Updated and improved XSpec generation and tests - now driven directly from SpecML source
* Adjusted gitignore; extended spec with more bindings; illustrator XSLT
* Added XSLT producing Markdown summary of requirements w/ examples; updates
* Added a small utility for converting JSON "prop" fields to "props" fields (emended 1.0.2 syntax)
* Updated to Profile Resolution spec (with example files now tagged) and readme.md
* Updated profile resolution (spec) readme with clarification regarding unit testing

…vid-waltermire-nist model, with example and schema; also cleanup

Prior work on pushing up the XSpec dependency and pulling in other
file relocation improvements were merged and it appears I pushed the
wrong commit into this branch and inadvertently led to more confusion
where builds failed in current version of #1754.

* XSpec test suites script & CI

* Helper script to build and tag the OSCAL env

* Move up Metaschema submodule

Prior work on pushing up the XSpec dependency and pulling in other
file relocation improvements were merged and it appears I pushed the
wrong commit into this branch and inadvertently led to more confusion
where builds failed in current version of #1754.

* Save XSpec test summary + pull appropriate tag

* Escape TEST_SUITE in XSpec runner

Co-authored-by: A.J. Stein <[email protected]>

* Update test script to address shellcheck guidance

* Grab branch from GHA

* Fix for builds on the M1

---------

Co-authored-by: A.J. Stein <[email protected]>