Modify UdpSocket::connect() to take SocketAddr by ref (#667)

[bobbo]

Change argument for UdpSocket::connect() to take &SocketAddr. This is more consistent with other UdpSocket methods, plus the TcpSocket::connect() method. Closes issue #667.

[KodrAus]

Thanks @bobbo! This looks good to me 👍

[carllerche]

This is unfortunately a breaking change :(

So, this can't be merged until an 0.7 release is planned. or UdpSocket::connect is deprecated in favor of UdpSocket::connect2 (and it is switched back or 0.7).

[carllerche]

If you are up for it, could you rebase this against the v0.7.x branch? I am using that as staging for v0.7.x

[bobbo]

Hi @carllerche, I've rebased on top of v0.7.x and changed PR target branch.