Share link provides incorrect URL

[nathanhaigh]

The share link button generates a URL which is not entirely correct.

It generates something like http://crobiad.agwine.adelaide.edu.au/dawn/jbrowse-prod/?loc=chr1D_part1%3A218553001..220417000 instead of http://crobiad.agwine.adelaide.edu.au/dawn/jbrowse/?loc=chr1D_part1%3A218553001..220417000

[nathanhaigh]

We should use a data-config as per: https://jbrowse.org/docs/embedding.html#embedding-directly-in-a-div and set shareURL as per http://jbrowse.org/docs/global_options.html