rewrite stacking algorithm and refactored line chart to leverage
refactor line chart
refactor bar chart to use new stacking algorithm
fix clip path x,y issue
fix ref line rendering
fix brush fade on bar chart
clean up
update version number
Merge branch 'master' into better-stack
fix stacking issue in line chart using stack layout
update bar chart stacking algorithm
fix bar stacking algorithm
fix line chart dot positioning
fix composite chart margin propagation issue
fix clipping test case
fix line chart rendering test case
update stacking css class name in test case
fix rendering test case
fix negative bar stacking algorithm
fix bar chart and composite chart test cases