Handle the ppa:bladerf/bladerf versions (#272)

This will permit bladerf-cli --version, etc, to show
something more usable, e.g.

rtucker@racer-x:~$ bladeRF-cli --version
0.11.0-2014.09-rc1-3-ppasaucy
rtucker@racer-x:~$ bladeRF-cli --lib-version
0.16.0-2014.09-rc1-3-ppasaucy

given debian version 2014.09-rc1-1ppa3~saucy