Lightweight implementation of Q.js for performance

Solves stack preservation when calling async functions without an await over async boundries

function testFn(){
    const deferred = Q.defer()
    async function a(){
        await Q.delay(1)
        throw new Error('test')
    }
    const promise = a()
    
    // will fail if this becomes awaited
    // this is because the stack is not preserved
    await Q.delay(10)

    const p = Q.cancelledRace([deferred.promise,promise])
    deferred.resolve()
    return await p
}

Stack would be lost (testFn) in this test over the Q.delay call. However with Q.safetyAwait method state can be preserved.

function testFn(){
    const deferred = Q.defer()
    async function a(){
        await Q.delay(1)
        throw new Error('test')
    }
    const promise = a()
    
    // will fail if this becomes awaited
    // this is because the stack is not preserved
    await Q.safetyAwait([Q.delay(10)], [promise])

    const p = Q.cancelledRace([deferred.promise,promise])
    deferred.resolve()
    return await p
}