Butterfly Images with Color Circles

Images from EOL
Merge remote-tracking branch 'upstream/master'
Updated color circle detection

8 November 2014: Detecting RGB color circles. 18 images tested, 15 with
circles. Of 15: 2 with 1 false positive, 2 with 1 circle missing, 1 with
all 3 circles missing. Of 3 without circles, 1 false positive.
Add test cases dir