Modify to record average sensor value

1. Fix the overflow problem
2. Display the average and variance of the interesting sensor
3. Add a new strip
Add new Response curve data
Add new calibration data
Fix a bug. Multiply a ratio to read data
Use the scale function to fix the bug in display

1. The display would "only" scale the image just before dispalying the strip
2. Set the magic number in the strip to 1.0f. i.e. the magic number would not affect the calculation