Updated GNU Radio and SDR driver Ubuntu packages

Alexandru Csete and Josh Blum have been busy putting together updated Ubuntu packages for GNU Radio plus various drivers, along with their dependencies. To summarise: Update to GNU Radio 3.7.9/volk 1.2 Latest gr-osmosdr with Red Pitaya support SoapyRedPitaya added UmTRX 1.0.8 Using UHD PPA The packages can be obtained…