Added support for the Thorlabs LCD and shutter controllers, and the Qubitekk Coincidence Counter

I've added support for the Thorlabs LCD and shutter controllers. These controllers are a bit tricky because Thorlabs echoes any commands sent to it. For the LCD I was able to get around this by setting two different terminators, for the shutter controller I just read an extra line. To get to this to work I had to add the read method to the generic instrument class. There might be a more elegant solution.

I also added support for the Qubitekk Coincidence Counter. (disclaimer: I work for Qubitekk and wrote the firmware and serial interface for this device). Feel free to remove the logo from the repository.

This should probably be wrapped into an ``IntEnum`` and made an [``enum_property``](http://instrumentkit.readthedocs.org/en/latest/devguide/util_fns.html#instruments.util_fns.enum_property).