Changed poser to return better values.

Instead of values in the half-open interval [0,360), it
now returns values in [-180,180).  Instead of 0 being
toward the left side of the image, 0 is now toward the
right side (as Descartes intended.)
Fixed bounding box bug in imageframe.
Added some debug code to the hopper.
Fixed bug and updated defaults.
Made user-requested changes to output format.
Lowered threshold from 60 to 30 until we sort the lighting.