Consider splitting out update events

[rikkertkoppes]

Working with a chromecast here. An update event is triggered when the device is first discovered. However, when chromecast switches application, it updates the txt field in the message, which sets the isNew flag, which triggers the update event as well.

I am only interested in really new devices, which is pretty much captured by all the other changes that set the isNew flag:

• change in port
• change in host
• change in address
• new serviceKeys

A change in data.txt seems like a peculiar one. I'd propose the following

• emit a serviceUp event (like mdns does) on the above 4 conditions (maybe ignoring subtypes as well?)
• emit an update event on the above 4 conditions and a change in data.txt (as is currently the case)
• maybe emit a message event on every packet that is received (that contains data)

In my specific case, commenting out browser.js:94 works, but that's a little harsh to do in general

[kmpm]

I agree.

This is something that I have wanted as well but there haven't been any time to fix it yet.