Work around failed requests from jbrowse

[shanewilson]

jbrowse generates bad requests. The segments concerned looks like this. They are in web-app/js/jbrowse/jbrowse.js, and there are two of them, for different cursors. Because these are coming from JavaScript, the URLs are relative to the requesting page, rather than the application, and you get messages like: "Exception occurred when processing request: [GET] /capsid/jbrowse/show/closedhand.cur". Simply, the URL is wrong. There are accesses to both closedhand.cur and openhand.cur

view.dragEnd = function(event) {
    dojo.forEach(view.dragEventHandles, dojo.disconnect);

    view.dragging = false;
    view.elem.style.cursor = "url(\"openhand.cur\"), move";
    document.body.style.cursor = "default";
    dojo.stopEvent(event);
    view.showCoarse();

    view.scrollUpdate();
    view.showVisibleBlocks(true);
};