rtl_fm: link librt
rtl_test: refactor tuner_benchmark
rtl_fm: handle no availible buffers
rtl_fm: arbitrary translation prototype
rtl_fm: remove unused resamplers
rtl_fm: software agc
driver: Jowett's tuning

This is a squashing of roughly 25 commits to assist with merging and
organization.  It will be rebased as various sections are mainlined.