This makes sure header checks work when the third party package is
installed in a non-standard location, as long as a pkg-config file is
found.

It is already defined by conf.define().

Release audio devices when alsa_driver_new fails

Call JackAlsaDriver::Close() when alsa_driver_new() fails, to
release devices acquired just before that call. Otherwise
JackAlsaDriver::Open() will never succeed again, as re-acquiring the
same device will fail with "A handler is already registered" DBus error.

fix missing void parameter in prototypes

Fix CPU hogging of the midi_thread()

The midi thread was always late after 2^31-1 Samples (~13.5h at 44.1kHz), because when there's no time limit, a uint64_t sample counter was compared against a signed 32bit INT_MAX to determine lateness. Now the CPU lockup will occur only after ~3 million years (at 192kHz), and because of the overflow it will presumably fix itself after a few milliseconds.

Fix 3 minor issues.

It's used for get_cycles() implementation, but it's never used.
On certain architectures it gives a warning which is be confusing.

It is maintained independently at: https://gitlab.com/lilrc/wafupdate

Forwarded from
<https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=728710>

Use _WIN32 instead of WIN32 in header files since WIN32 might not alw…

Implement new jack_port_rename API

JACK2 added this function first, but the int return has been always wrong.
When JACK1 added JackPortRenameCallback it used the proper return.

Now that JACK1 supports port renames, devs will start to use it.
(previously it didn't work properly because of the missing jack_client_t* arg)

Some code might be broken because of this, but it's a very simple change,
and existing code would have been broken when changing JACK1 to JACK2.

Finally, JACK2 code never uses the int return value of this callback.
So there's no real reason to NOT change this.

For instance, if compiling with gcc and the option --stc=c++11, WIN32 is not defined.
See http://webcache.googleusercontent.com/search?q=cache:amvfgAUCdsgJ:sourceforge.net/p/mingw-w64/mailman/message/31850993/+&cd=4&hl=en&ct=clnk&gl=no
http://sourceforge.net/p/mingw-w64/mailman/message/31850993/

Correct netmanager latency reporting