Just do:
sudo apt-get install build-essential libavahi-client-dev git-core libssl-dev
cd /usr/src
sudo git clone https://github.com/andoma/tvheadend.git
cd tvheadend
sudo ./configure
sudo make -j2
sudo /etc/init.d/tvheadend stop
sudo cp build.Linux/tvheadend /usr/bin/
sudo /etc/init.d/tvheadend start
If the previous version was from pulse, delete
sudo rm ~/.hts/tvheadend/dvr/config
and reconfigure the digital recorder in the web-frontend