Send broadcast messages to all interfaces

[aikar]

Look up all available interfaces and build an array of destinations for each for broadcast.

Resolves a TODO you had here.

Used a library to implement the logic of turning an address and netmask into a broadcast address.

Have tested this locally where I have 2 ifaces available (wireless and wired), another machine only had 1 (wireless)
Previously had issues where my outbound packets only went out wired, so the wireless client could not receive mine, however I could receive the wireless packets as I was also on wireless.

This resolves the issue by sending my outbound over both wired and wireless.

Resolves #26

[wankdanker]

Awesome. One thought I have is if options.address has been specified, then we should probably only resolve the broadcast address for the interface that has that address. Reason being, if I am specifying the address I want things bound to, I probably don't want packets broadcast on all interfaces.

It is possible that there is not an interface with the specified address though (sysctl -w net.ipv4.ip_nonlocal_bind=1), so, in that case I'd probably just broadcast to all interfaces.

[aikar]

@wankdanker this handles if the user DOES manually define broadcast as an option, to use what they supplied. Also expands the API to support passing an array instead of a single value.

The new code below only activates if the user did not manually declare broadcast.

[aikar]

Oh, to follow on that feedback i noticed you said address now and not broadcast.

I can see what you mean now. Not sure best way to implement that though.

I assume would have to compare address to cidr/netmask to compare?

Are you able to implement those changes? (you do have push to my branch for this PR)

[YindSoft]

Hi!, are you merging this fix? because I'm having the same issue, my node connects to the other nodes an receives data but those nodes doesn't know about mine and I can't send data. I change the code with this PR and it worked.