Added new filter for removing duplicate instances from the first batch of data received.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10133 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Updated javadoc.

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10134 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Test reference file for RemoveDuplicates

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10135 e0a1b77d-ad91-4216-81b1-defd5f83fa92
Initial import from Eibe

git-svn-id: https://svn.cms.waikato.ac.nz/svn/weka@10136 e0a1b77d-ad91-4216-81b1-defd5f83fa92