Top-level catalog for tests in the iXML Community Group Test Suite.

Tests have been contributed from several sources, but the core of the test collection are the tests contributed by Steven Pemberton in December 2021.

This test set collects some grammars with prolog information, and some simple tests to make sure the processor is actually processing the grammar normally.

The expected results currently assume that processors will recognize the version string "1.0" and no other version identifiers, and supply ixml:state="version-mismatch" in all cases where the version declaration is syntactically correct and the version string is not "1.0".