Extended the COLORS array in graph controller so that elections with multiple

candidates won't have graphs with dangerously similar colors. After 10
candidates though, they're on their own. Also added captions to the pref_tables
of the Schulze method to quickly explain how to read them. Feel free to
edit/move them. I tried to make them quick, explanatory and look-alikes to the
rest of the text, but definitely failed on the look-alike requirement. Please
fix...