[Pianod] pianod r176, pianod2 status

[Perette Barella]

pianod r176 is available with the development downloads.  It adds a --with(out)-polarssl option to configure.

pianod2 rooms now maintain separate mixes, and autotuning is in.  Issues related to crossfading/multithreading have been beaten down, along with addressing AVFoundation's crashy behavior and memory leaks (r170).

Here’s my experience with C++ compilers for pianod2:
* Clang (Apple LLVM): 6.0 & later work, 3.8 & earlier do not.
* gcc: 5.2 works, 4.9 & earlier do not.
Feedback on other C++ compilers or versions is appreciated.

Enjoy the holidays, all.

Perette