Removed untransformed E-values

Reading the MCL documentation, I realized that it requires edge weights to
increase with the strength of the relationship between the adjacent nodes. The
E-value instead decreases exponentially as the sequence alignment becomes more
statistically significant. After looking at the plots, I decided nothing was
gained by including them and removed them from my study. I actually made these
changes back in March, but forgot to commit them :-/

Signed-off-by: Ted Gibbons <ted.codes@gmail.com>
Updated title of legend

Realized that the legend had been incorrectly listing the color range as
indicating a linear relationship, when actually it was showing a logarithmic
relationship.  Made this change back in March, but I've since switched to using
stacked barcharts, which I find to be more useful, so I'm just getting around
to committing this change.

Signed-off-by: Ted Gibbons <ted.codes@gmail.com>