changed all uses of any(is.na(...)) to anyNA(...)


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/opm@622 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
* default of heat_map() changed from 'ward' to 'ward.D2'
* dependency on R >= 3.1.0 correctly noted


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/opm@623 edb9625f-4e0d-4859-8d74-9fd3b1da38cb