v1.4.2: Allow dynamically change advertising data

[arkhipenko]

This small change allows dynamically changing advertising data without a stop/start cycle.
I found it useful for changing the manufacturing data (for instance) frequently without affecting device's ability to be connected to or discovered.
refreshAdvertisingData() should be called after methods that alter the data, e.g. setManufacturerData(..)

[h2zero]

@arkhipenko Thank you for this, its a great idea. One thing that is missing is setting the scan response data to compliment this.

[arkhipenko]

Not quite sure what you mean by this, but maybe....
I came across this need because advertising data is a great way to communicate out without the need to be connected. Like presenting a sensor data or something along those lines. How does scan response come into play here?

[mhaberler]

I wasnt aware the response to an active scan might be different than the content of a periodic advertisement - good point

very much looking forward this capability!

[arkhipenko]

Ok, I read up on it and figured what this is about. I just didn't need the scan response, so didn't think about it. Yes, that capability would be a great compliment to adv. data.
Thanks.
I learn every day!

[h2zero]

@arkhipenko I will be adding this after #756 is merged. I will make a couple edits to account for this event, just wanted to let you know.