Toggle roiEnableButton and zoomControl when coordinates updated
Toggle roiEnableButton and zoomControl when coordinates updated

Resolves the issue reported here: https://groups.google.com/d/msg/igv-help/eqwVT7_Y1d4/rMvY9CVN8x8J, where roi button was persistently disabled.

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