Improvements:
- Added suppressions for memory leaks originating from OpenSSL and libp11 when
  running under LeakSanitizer (relevant mostly for commercial version)
- (commercial version only) Fixed a compilation warning in PKCS#11 integration

Bugfixes:
- Added missing #ifdefs to avs_stream_common.c, that prevented compilation when
  avs_stream component was disabled (contributed by https://github.com/anuar2k)
- Fixed implementations of avs_stream_read_t that did not handle NULL output
  pointers properly - this fixes some potential crashes in the HTTP client