Chage color.js to use class names rather than explicit colors.
Update color.js to color ans_array and MultiAnswer answer blanks when singleResult is 1.
Add coloring to GatewayQuiz, and make color.js take the correct/incorrect names as parameters rather than through hidden input fields (that seems a reak hack).  Modify Problem.pm to call color_input using the parameters rather than hidden fields, and fix up some spacing issues.
Fix undefined ARRAY reference in gateway quiz.
Fix problem with coloring multiple problems in a quiz, and with empty arrays of colored answers
Color inputs only when results are to be shown (this takes showPartialCorrectAnswers and the gateway parameters about showing scores into account).
Merge pull request #460 from dpvc/patch-input-colors

Patch for input colors (correct/incorrect)