Stop leaking OpenSSL types and defines in the isc/safe.h
requested to merge 1672-stop-leaking-external-headers-and-symbols-to-the-public-api-isc/safe.h-v9_16 into v9_16
The two "functions" that isc/safe.h declared before were actually simple defines to matching OpenSSL functions. The downside of the approach was enforcing all users of the libisc library to explicitly list the include path to OpenSSL and link with -lcrypto. By hiding the specific implementation into the private namespace changing the defines into simple functions, we no longer enforce this. In the long run, this might also allow us to switch cryptographic library implementation without affecting the downstream users.
(cherry picked from commit ab827ab5)
Closes #1672 (closed)