Chromosome indicator bars

[keller-mark]

Allow user to drag along a bar above/below genome-wide plots to show a different chromosome
Possibly just never limit to single chromosome, always load data for all (kind of already done for kataegis plot)
If so, create plots for all chromosomes, with only a single one visible initially (think of as window)

[keller-mark]

look into karyotype visualizations, such as those used in the UCSC genome browser