This is a simple test program for Mac bluetooth support.  It is still
missing read capability, because the Mac bluetooth framework lacks a
synchronous read function, i.e. there is no read analog to
IOBluetoothRFCOMMChannelWrite().  My initial attempts at setting up a
callback to handle input events have not worked, and I haven't had much
spare time to invest into this.

When this program is complete, it should be a simple matter to implement
bluetooth support into roboctl.

