The various LayersTestCase classes in core and full are hard to understand, partly because the main thing they do, calling LayersTest.test, is overly complex.

Split that method into two methods. One tests that all the available installations boot properly, the other does the module use analysis comparing 'test-standalone-reference' and 'test-all-layers.' Both can then be coherently javadoced, and the tests that call them can be as well.

For compatibility, deprecated and leave the test() method, having it just call the other two. It can be cleaned up later once the uses of it in full WF are removed.