ParticipatingNow status more robust to inactivity

[youralien]

Summary:

• pull from participating now when person who has hidden the window and redirect to home page...
• but do it with a delay, since accessing the camera module also activates hiding the Cerebro window

Tests:

• Tested with browser windows on laptop
• Tested with cordova apps with custom and external camera modules

Create 2 min timeouts to pull from participating now, to make sure accessing external camera modules doesnt trigger going back to the home page

Check if user is already participating, so as to not push when page is reactive

[youralien]

This is old, I don't think this is relevant anymore. Any important changes are already on master... I think