- Align README.md and GPR files with the fact that the server no longer compiles with the No_Secondary_Stack restriction.
- Fix include.am to reference the new name for the adc file.
Plus fix location of the certificate files in the examples.
Tested with both Ada examples:
```
obj/tls_server_main --psk
obj/tls_client_main 127.0.0.1 --psk
```
The Ada wrapper had an `&` operator for the verification mode. This
effectively caused the verification mode to equal `0`.
The operator has been switched to `or` now, in addition, a getter has
been added to the API. This allows for the test I've added to the server
code to verify that it is being set correctly.
`OPENSSL_ALL` flag added to Ada so that the verify mode getter function
is compiled in.
Fixes#7461
Thanks to @dalybrown for reporting it.