Made Z_MAX into an option.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10418 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Made Z_MAX into an option.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10419 e0a1b77d-ad91-4216-81b1-defd5f83fa92