Fix #37 Flapi not working on MacOS (ports specifically)

[gavin2059]

Addresses issue #37

2-step fix here, although you only need 1 to get it working:

Fix 1: open_ioport for Auto Port Creation
Fix flapi creating ports itself on mac. We need to use the mido function open_ioport instead of open_input and open_output.

From here, the README instructions should work.

Fix 2: IAC Driver Port Name Matching for Manual Port Creation
For Audio MIDI Setup ports to work, we need to edit the open_port function slightly. The current code assumes that the drivers will be named exactly "Flapi XXX" with a number suffix. However, the mac driver created ports are always detected as "IAC Driver Flapi XXX". So this code will never find IAC Driver ports.

After doing this, I was able to connect to IAC ports, or have FLAPI create its own ports, and produce a healthy heartbeat.

[MaddyGuthridge]

Thanks so much for this contribution! My main concern is that this may (further) break the logic for the Windows side of things. I don't have time to test it myself currently (plus the main branch is in a half-rewritten state), but I'll keep this open in the hope that I have the time to review it in the future.

[gavin2059]

No worries!

I think it should be fine because users have to create ports manually on windows anyways so the open_ioport thing shouldn't affect windows?

open_port changes should be pretty safe too. The only edge case I can think of is if they somehow had a port named IAC Driver Flapi Request/IAC Driver Flapi Response that isn't used for Flapi.

Totally understand where you're coming from tho. Thanks so much for making Flapi!