qtgui: can set the update rate for drawing the time raster plots. Maintains column alignment of incoming data.
qtgui: allows setting of update rate in GRC for all QTGUI plotters.
channels: adding Rayliegh/Rician fading model
channels: adding grc definition for fading_model
qtgui: fixed duplication of time raster auto scale menu item.
qtgui: fixed a blank line issue in time raster plots.
qtgui: fixing time raster axis and picker labels.
Merge remote-tracking branch 'osh/next' into next
channels: adding simple QA for fading model. Doesn't really test much but that it runs.
channels: updating copyright year.