What to do before 1.0 release

[mensonen]

Now that the 0.9.0 release is out, and as several of the past commits have just been 3GPP interface support additions, I think this project is approaching a stable 1.0 release.

Here's a collection of things that I think should be done before 1.0:

• Diameter Sh interface, 3GPP TS 29.212
• Diameter Gx interface, 3GPP TS 29.212
• Diameter Rx interface, 3GPP TS 29.212
• Diameter Re interface, 3GPP TS 32.296, however I'm not so sure how final this spec is. The document still contains a lot of notes and open questions
• Verify that Diameter SIP application support is fully there, RFC 4740. The commands are shared with Cx/Dx, but I don't think every AVP is implemented
• Review and rename every attribute that's flagged as incorrect by test_annotations.py
• Implement AvpEnum as actual Enums (see Proof of concept for replacing int in constants.py with IntEnums #56)

This should be also, in general, the final chance to do changes that break backwards compatibility.