Clean up use of SSL_*_app_data functions
Commit 49de5431d53b made Tor use
SSL_get_app_data instead of its previous hash table to look up the
tor_tls_t * object corresponding to an
SSL * object. Unfortunately:
- The patch left in two hash-table helper functions that it made unused. Reported by mobmix.
- The patch did not check the result of
SSL_set_app_datafor errors. Reported by piebeer.
SSL_*_app_datafunctions are actually macros wrapping corresponding
SSL_*_ex_datafunctions in such a way that a program that tries to use the
ex_datafunctions at the same time will break horribly.