argument 'teststat' now accepts values "maximum" and "quadratic"

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@901 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
class "IndependenceTestStatistic" is now virtual

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@902 edb9625f-4e0d-4859-8d74-9fd3b1da38cb