JACK 0.121.3 is a bug fix release containing (almost) no new
functionality. It is required if you want to use JACK1 on OS X with
any clients that use weak linkage for JACK feature detection (e.g.
* Make the printed output of jack_iodelay more useful to actual users
* Compilation fixes for OS X (particularly PPC architectures)
* Remove SSE-related messages during startup
* Fix a few argument type declarations for a few functions
* OSS backend: fix a call to yet undefined engine instance