BVAL-349 ("Mark spec sentences as TCK-relevant in order to generate audit file")

This pull request comprises the following changes:

* New XSL transformation for creating the tck-audit.xml file based on marked sentences in the spec
* Added `role="tckTestable"`, `role="tckNotTestable"` etc. to the spec chapters
* Added statements for implicit TCK assertions to the spec in order to be able to generate these assertions, too
* Added Ant task for running the transformation

The tck-audit.xml file generated based on this pull request resembles the latest BV 1.0 audit file (i.e., new assertions will be added separately).