HUE-141: Shell app should be immediately restorable

Review Request #1826 - Created June 16, 2011 and updated

Aditya Acharya
The shell app supports restoration up to a point. If the subprocess backing an instance of the shell app is still running, the cached output and commands are provided on app launch and the user regains control of the same subprocess.

Previously, the state of the shell app was stored only in a periodic POST request, and as a result, the app could only be restored after some time had passed.

This commit changes the JS so that it sends an out-of-band POST request immediately to support immediate restoration of the app.
Started Hue, created a subprocess by picking something from the menu.

Started another browser and logged in to Hue as the same user immediately. Verified that app restores successfully.