RFR 8214794 : java.specification.version should be only the major version number

[Roger Riggs]

Please review correctly setting the java.specification.version property
with only the major version number.  A test is added to ensure the
java spec version agrees with the major version.

The symptoms are that jtreg would fail with a full version number.

Webrev:
   http://cr.openjdk.java.net/~rriggs/webrev-spec-ver-8214700-2/

Thanks, Roger