* Improve nginx setup to transfer auth information to the fcgiwrap
backend.
* Add instructions for creating client certs for testing.
* Add debug output to see if and which client cert has been used when
calling the csaf_provider.go .
* Add instructions for installing a TLS server certificate on nginx
* Fix link to nginx in README.md
* List all three ways to get a webserver TLS certificate. With some
hints on which to chose for which purpose.
* Do not add CSR instructions, because they can change over time and each CA may
have slightly different requirements.
* Add a hint about setting protocol selection.
* Fix typo in provider-setup.md
