Re: Current Firmware
It looks like what you are trying to compile is, the code you would see if you clicked on "view source code" in your browser while looking at the code on GitHub. Of course, it is possible that something was temporary wrong at GitHub when you tried to download the code.
Try this link to download the zip file for the code. https://github.com/afarhan/ubitx4/archive/master.zip
I believe the CEC firmware has compiled HEX files available. There were instructions for how to install a program on Windows that could program an Arduino from the HEX file. In my case, as I have a Mac, it was just easier to compile the CEC software and upload it from the Arduino Sketch.
Hopefully the number of errors you get, if any, will be simple "not found" errors as Jack mentioned. Those would be the libraries you would install from the "Sketch", "Include Library", "Manage Libraries" dropdown. Jack also points out that libraries can be downloaded directly from URLs, but I think anything needed for the factory firmware would be obtainable using the Sketch user interface.
Hang in there, much of programming and compiling seems counterintuitive. But, once you begin find your way around it starts to make sense. Once it all makes sense you've gone off the deep end and become a real programmer.
Side note: Hmmm. Maybe all those dire warnings about Microsoft and GitHub have so quickly become reality. After all, look at the first error:
"warning: missing terminating ' character
Microsoft is acquiring GitHub!"
The deal hasn't even closed yet, and here we are...