solver out and made it a separate class.  The kernel_matrix_cache has also
been removed in favor of the new symmetric_matrix_cache.  Finally, the
remaining bits of the svm_nu_trainer have been moved into svm_nu_trainer.h

Also note that invalid_svm_nu_error has been renamed to invalid_nu_error.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403994