clusterCluster: calculates overlaps between two clusterings
In raim/segmenTools: analysis of genome segmentations by segmenTier

calculates mutual overlaps between two clusterings of the same data set using hypergeometric distribution statistics for significantly enriched or deprived mutual overlaps; TODO: specify wich cl will be rows/columns and to which percent refers to

1 2	clusterCluster(cl1, cl2, na.string = "na", cl1.srt, cl2.srt, alternative = c("greater"))

`cl1`	clustering 1; a vector of cluster associations or an object of class "clustering" by segmenTier's `clusterTimeseries`
`cl2`	clustering 2; see argument `cl1`
`na.string`	replace NA or empty strings by ‘<na.string>’
`cl1.srt`	optional cluster sorting of clustering 1
`cl2.srt`	optional cluster sorting of clustering 2
`alternative`	a character string specifying the alternative hypothesis, must be one of ‘"greater"’ to calculate enrichment (default), ‘"less"’ to calculate deprivation, or ‘"two.sided"’ to report the more more signficant p-value of both