Add dialog for entry of bam index  URL if not found.
Add dialog for entry of bam index  URL if not found.

igvteam/igv,amwenger/igv,igvteam/igv,igvteam/igv,amwenger/igv,amwenger/igv,igvteam/igv,igvteam/igv,godotgildor/igv,godotgildor/igv,godotgildor/igv,itenente/igv,amwenger/igv,godotgildor/igv,itenente/igv,itenente/igv,amwenger/igv,itenente/igv,itenente/igv,godotgildor/igv