minor css cleanup
a few debugging utils
implement some feature requests

1. eliminate EC50 & AUC
2. more tick marks
3. larger plot markers
make tooltips easier to hit
make legend bullets match markers
fix plot labels
implement log2 Hill Slope

% cutt 1,2,3,7,8,9,11 dose_response_data.tsv > scatterplot_data.tsv
% hdrs scatterplot_data.tsv
==> scatterplot_data.tsv <==
1	cell line
2	drug
3	target
4	log10[IC50 (M)]
5	log10[GI50 (M)]
6	HillSlope
7	E_max
% inplace pflane '$F[5] = $. == 1 ? "log2[" . $F[5] . "]" : sprintf("%.4f", log($F[5])/log(2)); print @F' scatterplot_data.tsv
% perl -i -lpe 's/\tnan\t/\tNaN\t/g' scatterplot_data.tsv
fix omission in scatterplots help
re-implement open-close icons