Add an option for displaying {percentage, value, or value(percentage)} for the label on the pie slices.
Add an option for displaying title for chart legend.
Merge pull request #55 from midoringo8823/bug_fix

Add a check for height < 0 and and force height to be 0 so bar chart doe...
Merge pull request #54 from midoringo8823/pie_legend_options

Add an option for displaying {percentage, value, or value(percentage)} f...
up the release number for pull
Merge pull request #56 from midoringo8823/release

up the release number for pull
bug fix, Add more logic to the stacked bar chart rendering, previously, the offset between bar can still be off base on how much less the computed bar height is less than the sperator and stroke width.  For example, a bar with computed height 0 and computed height 3 will both have final height of 0, but the bar with original height 3 would have created an offset space on the screen, so the next drawn bar will need to have less offset so we don't end up with a big blank between bars.