Now stores a reference to the training data's structure, and only clears the pre-built classifier list in buildClassifier() if there are filenames of classifiers to load specified.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@9762 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Updated listOptions descriptions.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@9765 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Javadoc fix.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@9766 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Changes courtesy of Sean Daugherty that save memory and improve the speed of LinearRegression

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka/trunk@9768 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Merge remote-tracking branch 'upstream'