[TAP,UWS] Add a protocol version number for UWS and TAP:

  - uws.service.UWS.VERSION  (static final)
  - tap.resource.TAP.VERSION (static final)

Dealing with several protocol versions in the same time is quite difficult and
may significantly alter the libraries API in an unstable way. That's why, for
the TAP and UWS libraries, only one version is implemented (i.e. the last one).
To use a older version of the protocol, one must use an older version of the
corresponding library.

About the versioning of the ADQL standard, there is no need to set any version
number somewhere because a different ADQL version implies a different grammar.
It means that a different parser is required for each ADQL version. For the
moment, there is only one version, so no need to change anything to the ADQL
library about ADQL version. Later, ADQLParser should become an interface and
a factory will have to be used in order to get the parser corresponding to the
desired ADQL version.

src/tap/resource/TAP.java

@@ -60,6 +60,10 @@ import uws.service.log.UWSLog.LogLevel;
  */
 public class TAP implements VOSIResource {
 
+	/** Version of the TAP protocol used in this library.
+	 * @since 2.1 */
+	public final static String VERSION = "1.0";
+
 	/** <p>Name of the TAP AVAILABILITY resource.
 	 * This resource tells whether the TAP service is available (i.e. whether it accepts queries or not).</p>
 	 * <p><i>Note: this name is suffixing the root TAP URL in order to access one of its resources.</i></p>

src/uws/service/UWS.java

@@ -64,10 +64,14 @@ import uws.service.request.UWSRequestParser;
  * </b></p>
  *
  * @author Gr&eacute;gory Mantelet (CDS;ARI)
- * @version 4.2 (06/2017)
+ * @version 4.2 (09/2017)
  */
 public interface UWS extends Iterable<JobList> {
 
+	/** Version of the UWS protocol used in this library.
+	 * @since 4.2 */
+	public final static String VERSION = "1.0";
+
 	/** Attribute of the HttpServletRequest to set and to get in order to access the request ID set by the UWS library.
 	 * @since 4.1 */
 	public static final String REQ_ATTRIBUTE_ID = "UWS_REQUEST_ID";