Motivation:
When the OpenSslContext is gc'ed and the user still hold a reference to OpenSslSessionContext / OpenSslSessionStats it is possible to produce a segfault when calling
a method on any of these that tries to pass down the ctx pointer to the native methods. This is because the OpenSslContext finalizer will free the native pointer.
Modifications:
Change OpenSslSessionContext / OpenSslSessionContext to store a reference to OpenSslContext and so prevent the GC to collect it as long as the user has a reference to OpenSslSessionContext / OpenSslSessionContext.
Result:
No more sefault possible.