There's already a kplugin which makes the job.
It searches for a new stable version, and download it or ask for downloading it.You have then to install
Don't forget that 1.6 and 1.7 are beta and aren't seen by the kplugin.
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:38.0) Gecko/20100101 Ubuntu/12.04 K-Meleon/76.0
Mail : alain [dot] aupeix [at] wanadoo [dot] fr
Ubuntu 12.04 - Gramps 3.4.9 - Harbour 3.2.0 - Hwgui 2.20-3 - K-Meleon 76.0 rc