Making OSSO default JACK option

Hello,

First and most important, all kudos go to Florian for doing amazing work 
on JACK and his new audio library: OSSO. Before building JACK with this 
option, Ardour showed DSP 90ish percent busy. With OSSO, it's around 
12%. Naturally, I am more than interested in making it a default port 
option, so I just wanted to report my findings. I would like to thank 
you for the timing, too, as I have a album recording that's waiting for 
me. :o)

Regards,
meka