[Media_api] Core Midi empty port name problems

[Roger Dannenberg]

Hi Rob,
    I was just staring at a stack trace trying to figure out what could 
have gone wrong in EndpointName, but I don't have the right hardware to 
tickle the bug. Thanks *very* much for your timely fix -- we're seeing 
if it fixes another apparently related crash, and if it works there too, 
I'll integrate the change.
    Yes, that was me that "Fixed bug in midi_length function in OS X 
implementation" -- there was some untested OS X-specific code for 
handling Midi Time Code. I'll post a new download and announce to this 
list when things settle down.
    -Roger