remove deprecated ds.subset/subsetDS and tidy up some code

Author: davraam

NAMESPACE

@@ -102,7 +102,6 @@ export(ds.seq)
 export(ds.setSeed)
 export(ds.skewness)
 export(ds.sqrt)
-export(ds.subset)
 export(ds.subsetByClass)
 export(ds.summary)
 export(ds.table)

R/ds.meanByClass.R

@@ -31,7 +31,6 @@
 #' @export
 #' @author DataSHIELD Development Team
 #' @seealso \code{\link{ds.subsetByClass}} to subset by the classes of factor vector(s).
-#' @seealso \code{\link{ds.subset}} to subset by complete cases (i.e. removing missing values), threshold, columns and rows.
 #' @examples
 #' \dontrun{
 #'

R/ds.meanSdGp.R

@@ -68,9 +68,6 @@
 #' across studies and/or separately for each study, depending on the argument \code{type}. 
 #' 
 #' @author DataSHIELD Development Team
-#' @seealso \code{\link{ds.subsetByClass}} to subset by the classes of factor vector(s).
-#' @seealso \code{\link{ds.subset}} to subset by complete cases (i.e. removing missing values), threshold,
-#' columns and rows.
 #' @export
 #' @examples
 #' \dontrun{

R/ds.subset.R

@@ -16,7 +16,6 @@
 #' @return a no data are return to the user but messages are printed out.
 #' @author Gaye, A.
 #' @seealso \link{ds.meanByClass} to compute mean and standard deviation across categories of a factor vectors.
-#' @seealso \link{ds.subset} to subset by complete cases (i.e. removing missing values), threshold, columns and rows.
 #' @export
 #' @examples
 #' \dontrun{