Added little utility to find color matching function peak wavelengths and values.

Used in PrintPhotoreceptors.

Signed-off-by: David Brainard <brainard@psych.upenn.edu>
Cleaned up PrintPhotoreceptors some, and little bit of small bug swatting in FillInPhotoreceptors and DefaultPhotoreceptors.

Verified that the main unit tests that use this stuff still run OK.
  IsomerizationsInEyeDemo
  IsomerizationsInDishDemo
  CIEConeFundamentalsTest
  FitConeFundamentalsTest

Signed-off-by: David Brainard <brainard@psych.upenn.edu>