Calculates the distribution of distances from a query set to closest TSS

Given a query GRanges object and an assembly string, this function will grab the TSS list for the given reference assembly and then calculate the distance from each query feature to the closest TSS.

TSSDistance(query, refAssembly)

Arguments

query	A GenomicRanges or GenomicRangesList object with query regions
refAssembly	A character vector specifying the reference genome assembly (*e.g.* 'hg19'). This will be used to grab chromosome sizes with getTSSs.