Smart Intervals 
setInterval replacement for asynchronous tasks
var smartInterval = require('smart-intervals')
interval = smartInterval(1000, function(callback) {
doAsyncActiviy(callback)
// interval will be called again 1000ms after doAsyncActiviy calls its callback
})Methods
interval.stop([callback])
Clears the interval.
If the interval was waiting for the next run it calls the optional callback immediately.
If the interval is waiting for its async function to return it calls the optional callback once the async function finishes
interval.runNow([callback])
Skips waiting for the interval and calls the function immediately if not already running.
Calls the optional callback once the async function finishes