updated documentation for covariance matrix
updated documentation for covariance matrix


petricm/LCIO,iLCSoft/LCIO,petricm/LCIO,petricm/LCIO,petricm/LCIO,iLCSoft/LCIO,iLCSoft/LCIO,iLCSoft/LCIO,iLCSoft/LCIO,petricm/LCIO,iLCSoft/LCIO,petricm/LCIO