start on new errors
update count_devices
change PmDeviceID = int to PmDeviceId = i32
change int to i32 where possible
PmDeviceInfo -> DeviceInfo
PmDeviceId -> PortMidiDeviceId
add headings for different sections of code
update get default devices
update PmEvent and PmMessage
update PmInputPort
update PmOutputPort
remove PmError
update ffi.rs
return bool from has_host_error