Adding and killing background jobs.

The weird things it does are:
- receive an Execution start (that will start a background job)
- when receiving a JobStarted event, it flags the later execution
- when the execution ends, we artificially keep it alive
- until the job ends
New sbt-rc version and uses echo when running
Moves to sbt 0.13.6 and also latest published versions of sbt-rc and sbt-echo

Conflicts:
	ui/app/assets/plugins/run/runPluginHandler.js
Adding and killing background jobs.

The weird things it does are:
- receive an Execution start (that will start a background job)
- when receiving a JobStarted event, it flags the later execution
- when the execution ends, we artificially keep it alive
- until the job ends
Remove the cranky blinking when loading an sag file (or reduce it at least)
Code: remove footer with nothing in it!
Misc updates to run/actor pages
Fix

Conflicts:
	ui/app/assets/plugins/run/actors/actors.html
	ui/app/assets/services/inspect/runPluginHandler.js
	ui/app/assets/services/sbt/tasks.js
	ui/app/assets/widgets/openIn/openIn.js
Small arrangements for the ui
First step towards handling of sbt plugins for background run and Inspect. Uses modal window during the installation process.

tmp

Conflicts:
	ui/app/assets/plugins/run/actors/actors.html
	ui/app/assets/plugins/run/run.js
Change the way we configure echo