GrCharts: Generate share bar charts in HTML

This is a class meant for generating bar charts on which each bar is represents a share value relative to a given starting total value. It can be used to generate charts for presenting poll results.

The class generates HTML tags for each bar in the chart in several styles that are available like using images to draw the bars or just output the percentage value that each bar represents.

The class may also return in an array the HTML tags for all bars in the chart.