More informative display of "tuned results"

[alvestrand]

The "tuned results" display is not optimal for comprehension.
Suggested alternate graphic:

• Use color to differentiate the two codecs
• Include the -single-criterion as a line (currently not included)
• Include the "tuned results" as bullets, not as a connected line
• Shape the "tuned results" that fail to achieve the criterion (negative score) as X, not bullet.

The graph generation is done purely in Javascript. The information needs to be easily accessible.

[alvestrand]

#44 added tuned results displayed as a dotted line, and the single-criterion as a solid line.