create separate class for plotting variables over time.
create separate class for plotting variables over time.

Change-Id: Ie35e5fd4d7cad31598931f75dba9dba8d3369158
TODO: Additional metrics, RoI bugfixing (first click doesn't register, changing options deletes RoI), Add scaling to RoI, clean up code

IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense