Write image of Raspbian Jessie with PIXEL desktop to micro SD card (www.raspberrypi.org/downloads/raspbian/, tested for ver. 2016-11-25)

Start Raspberry Pi and execute the below commands/steps. Set initial passwords. 

Installation
------------
#total time of installation: about 20 minutes; measured for: RPi 3, class 10 SD card, 20Mb/s Internet download speed
#time of downloading and installing updates may vary

#Change the default password for security reasons!
passwd

#Tuners firmware (download from the Internet and save to /lib/firmware/ directory)
sudo curl -o /lib/firmware/dvb-usb-it9135-01.fw 'https://github.com/OpenELEC/dvb-firmware/raw/master/firmware/dvb-usb-it9135-01.fw' -L
sudo curl -o /lib/firmware/dvb-usb-it9135-02.fw 'https://github.com/OpenELEC/dvb-firmware/raw/master/firmware/dvb-usb-it9135-02.fw' -L

#Additional packages repositories and OS update (~11 minutes)
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 379CE192D401AB61
echo 'deb http://dl.bintray.com/tvheadend/deb jessie release' | sudo tee -a /etc/apt/sources.list #Tvheadend 4.0.8, Jessie is Debian current version
                                                                                                  #todo: update the name when changed
sudo apt-get update && sudo apt-get -y -q upgrade         #-q otherwise displays some information and asks to press Q(uit) key; we do not use
                                                          #PiBakery since it would hang after asking which '/etc/lightdm/lightdm.conf' file
                                                          #to use - the one from the system or the updated one
#Packages installation and preconfiguration (~ 8 minutes)
sudo DEBIAN_FRONTEND=noninteractive apt-get -y install tvheadend  #(~ 6 minutes) will not ask about admin name and password during installation
sudo apt-get -y install tightvncserver xrdp               #(~ 2 minutes) Microsoft Remote Desktop (RDP)
                                                          #tightvncserver package is required for uninstalling RealVNC since Raspberry Pi 3
sudo apt-get -y install mc htop                           #Midnight Commander file manager and htop system monitor (set Hide userland threads: on)
sudo apt-get -y install unattended-upgrades               #(~ 15 seconds)
sudo apt-get -y install expect                            #(fast) used to change Tvheadend admin password in command line in automated configuration

in /etc/apt/apt.conf.d/20auto-upgrades file set: APT::Periodic::Update-Package-Lists  "1";
                                                 APT::Periodic::Unattended-Upgrade    "1"; 
in /etc/apt/apt.conf.d/50unattended-upgrades file uncomment and set: Unattended-Upgrade::Origins-Pattern       { ... "o=Raspbian,a=stable"; ... }
                                                                     Unattended-Upgrade::Automatic-Reboot      "true"
                                                                     Unattended-Upgrade::Automatic-Reboot-Time "03:30";
                                                                     Acquire::http::Dl-Limit                   "2048";
in /etc/default/rcS file uncomment and set: FSCKFIX=yes  #try to automatically repair problems with file system consistency
                                                         #(otherwise Raspberry Pi will stop during boot and wait for human intervention)

#Restart Raspberry Pi (to activate the firmware and to be sure that all changes are saved to SD card)
sudo reboot

Initial Tvheadend configuration (without setting multiplexes)
-------------------------------------------------------------
sudo dpkg-reconfigure tvheadend           #set/change Tvheadend admin name (to "tvadmin") & password
configure Tvheadend on raspberrypi:9981
 - Access control                         #add "tvuser1-.."
     Enabled:            yes
     Username:           tvuser<1-..>
     Password:           <password>
     Network prefix:     0.0.0.0/0,::/0   #for computer with any IP address (default value)
                         192.168.1.1/24   #ex. for all computers in local network with 192.168.1.* IP addresses
                         a.b.c.d/32       #ex. for one computer with a.b.c.d IP address, where a-d are numbers between 0 and 255
     HTSP Streaming:     yes              #TV can be watched in Kodi
     Limit Connections:  4                #how many streams can user watch at the same time, default is 4
 - DVB Inputs:
   - Networks:                            #define a "TV network"
     Type:               DVB-T
     Network name:       MyNet
     Network Discovery:  no               #doesn't search for new multiplexes automatically
   - TV Adapters:                         #for each TV adapter set:
     Enabled:            yes
     Name:               any unique name
     Networks:           name of the previously added TV network
     Power Save:         yes              #unused TV adapters will save power
     Priority:           <number>         #set it optionally to control in which order TV adapters are used
     Force old status:   yes              #otherwise sometimes TV signal strength and quality are shown incorrectly (tvheadend.org/issues/2759 bug)

(for testing and configuration purposes:
  - configure multiplexes, services and channels for testing location, they should be removed after tests
  - enable SSH, it will be disabled after changing passwords)