Various tweaks

[sfgeorge]

• Little fixes to From, Contact, and Route headers
• Ensure BYEs work through proxies

[bklang]

Is this change compatible with what was there before? The SIPp docs say:

If the "rrs" attribute in a recv command is set to "true", then the [next_url] contains the contents of the Contact header (i.e within the '<' and '>' of Contact)

If rrs is not set to true, what will [next_url] expand to?

[sfgeorge]

I'm relying on the rrs in the initial #receive_answer to be true. Without that, I believe that [next_url] would yield an empty string and break the entire exchange.

[bklang]

When you say the rrs in #receive_answer, are you referring to this: https://github.com/bklang/sippy_cup/pull/15/files#L1R111 Right now it appears to be hard coded, but your other PR might make that no longer the case.

[sfgeorge]

Yep, exactly. I did happen to make changes to it in #15. But there rrs still defaults to true if not explicitly overridden. I believe that [next_url] in BYE would only break if someone explicitly set rrs to false for some reason.

[bklang]

Thanks @sfgeorge! Looks good, merging.