geneRegionBiomart: Construct an AnnotationTrack object from biomaRt.
In GenomeGraphs: Plotting genomic information from Ensembl

This function constructs an AnnotationTrack object from Biomart. It is a convenience function.

1	geneRegionBiomart(chr, start, end, strand, biomart, dp = NULL, chrFunction = function(x) x, strandFunction = function(x) x)

`chr`	`chr` An integer
`start`	`start` The start location
`end`	`end` The end location
`strand`	`strand` An integer -1, 0, 1
`biomart`	`biomart` A mart
`dp`	`dp` DisplayPars object
`chrFunction`	`chrFunction` A function which takes `chr` and converts it into the correct representation for biomaRt. For instance yeast likes to have chromosomes as roman numerals so you can use as.roman here.
`strandFunction`	`strandFunction` Analagous to chrFunction, but for strand. The internal representation of strand is -1,0,1 whereas biomaRt has different species dependent representations.