Capabilities now cover missing class values so that it is possible to use it for semi-supervised learning

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@10002 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Forgot to update the Changes entry

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@10003 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Merge remote-tracking branch 'upstream'