added DD RFE mode to list of modes that are I-only
added HDR mode to list of I only modes
add persistence gradient editor
use DEFAULT_SAMPLE_TYPE instead of new property
Merge pull request #3 from wardi/fix_dd_axis

use DEFAULT_SAMPLE_TYPE instead of new property
exponential>linear
scale freq axis
fix playback of old recordings
Merge remote-tracking branch 'wardi/fix-old-recording-playback' into persistence_plot
Merge remote-tracking branch 'wardi/persistence_plot' into persistence_plot