Upgrade Bluez on Raspbian

sudo apt-get update
sudo apt-get install libdbus-1-dev libglib2.0-dev libudev-dev libical-dev libreadline-dev -y
wget www.kernel.org/pub/linux/bluetooth/bluez-5.50.tar.xz
tar xvf bluez-5.50.tar.xz && cd bluez-5.50
./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-experimental 
make -j4
sudo make install
sudo reboot
bluetoothctl -v

Synology

"I had to make some modification in Synology, because optware has not got every packages. After I disabled udev and systemd I was able to compile ./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-experimental --disable-udev --disable-systemd"