Implement full OpenCV pipeline

[macuser47]

The back end will need to properly apply all of the preferences in the vpr format:

• area_max - Max percent of screen area for a contour
• area_min - Min percent of screen area for a contour
• aspect_max - Max width/length ratio for a contour
• aspect_min - Min width/length ratio for a contour
• blue_balance - ?
• calibration_type - ?
• contour_grouping - ?
• contour_sort_final - Order to sort the contours by
• convexity_max - Fullness upper bound - unknown units
• convexity_min - Fullness lower bound - unknown units
• cross_a_a - ?
• cross_a_x - x (coord ?) of contour "crosshair"
• cross_a_y - y (coord ?) of contour "crosshair"
• cross_b_a - ?
• cross_b_x - x (coord ?) of second contour "crosshair"
• cross_b_y - y (coord ?) of second contour "crosshair"
• desc - Pipeline description string
• desired_contour_region - ?
• exposure - Exposure of camera in ms
• hue_max - HSV H upper bound
• hue_min - HSV H lower bound
• image_flip - [0, 1] - whether the camera image should be fipped
• image_source - int describing camera image source -- maybe for static image tuning?
• img_to_show - index of the snapshot to use for static image tuning
• red_balance - ?
• sat_max - HSV S upper bound
• sat_min - HSV S lower bound
• val_max - HSV V upper bound
• val_min - HSV V lower bound