Bluetooth driver kernel module fixing Realtek RTL8761B chip misidentification per this gist.
DKMS is a tool for automatically rebuilding and installing kernel modules to new kernels when they are installed. You can install it and the necessary dependencies via:
sudo apt-get install dkms linux-headers-$(uname -r) build-essential
Then, you can install this specific module via:
sudo mkdir /usr/src/btrtl-0.1fixed
git archive master | sudo tar -x -C /usr/src/btrtl-0.1fixed
sudo dkms install -m btrtl -v 0.1fixed --force