This should fix the last anomalies when looping audio items...

The audio items should be mostly usable now, at least in the testing
I've done...  Some of the features aren't implemented yet, but what
is implemented seems to be pretty f'ing solid...

Competitors(you know who you are, and I know you're reading this):
I tracked down these bugs by using that 'debugger' project in
tools/debugger.  It loads PyDAW into a simulated environment
without Jack or ALSA where I can then play back an entire project
through GDB just as if a user was interacting with it, but I can step
through the code line-by-line without my audio interface freaking out.
I can also run a full project through Valgrind the same way, but just
the back-end so that I don't get the 1,000,000,000 Qt Valgrind errors.

Just in case you were wondering why my shiny new code is already so
incredibly stable...  but hey, just keep on slandering me and
accusing me of 'cheating' by writing my own host instead of banging
my head against a wall trying to do the impossible and make my
plugins work in your hosts...  Users will continue not to care,
and PyDAW will only benefit from your word-of-mouth non-advertising.