what is modified about Extauth responses: log strange responses and add timeout in ver 2.1.0-rc2 ?

I get the readme of ver 2.1.0-rc2, and find:

* Authentification
- Extauth responses: log strange responses and add timeout

But when i installed it, i donot find any describe about "Extauth responses: log strange responses and add timeout" in guide.pdf.

so, any one please tell me, what is modified aboute extauth in ver 2.1.0-rc2?