DSAPI version tags

Version tags

The code has a class Version in the data_api package which provides Version.string and Version.tagname. This class is created by the POM when doing the generate-sources phase and sets Version.string to the project version string and Version.tagName to the value of the property project.tagname. (The tagname exists to make it easier to track evolving snapshots during development.)

When the DSAPIManager class starts up, it logs the version string and tagname. When it creates a SPARQL query, that query starts with a comment with the version string and tagname.