PS4 support

[Beyley]

Feel free to split these tasks into separate issues, or just solve them both in one PR.

@MindOfBog has offered help here, since they have a modded PS4.

• Support PS4 digest
• Support PSN OAuth

[jvyden]

Here's all I know about PS4 OAuth:

• Game sets URL parameter in /login, &oauth=1
• Body is in this format: <username>:<code>
• I do not know if there is any way for us to verify this code to legitimately come from that user, there is no signature like NP tickets, and we definitely can't just create our own OAuth application. We will have to use IP authentication.
• Someone has had this previously working with Refresh. We ended up banning that user for unrelated reasons. We know it's at the very least possible.