UI: adding classes to download, run and stop buttons. only showing the explorer menu when in javascript view.
UI: adding classes to download, run and stop buttons. only showing the explorer menu when in javascript view.

playi/pxt,switchinnovations/pxt,Microsoft/pxt,switch-education/pxt,switch-education/pxt,Microsoft/pxt,Microsoft/pxt,playi/pxt,switch-education/pxt,switchinnovations/pxt,Microsoft/pxt,switchinnovations/pxt,Microsoft/pxt,switchinnovations/pxt,switch-education/pxt,playi/pxt,playi/pxt,switch-education/pxt