Add ability to use data ids in label formatting on pie chart slices
fixed error caused by function in config.data_order
added test for function in config.data_order
Merge pull request #599 from Moussekateer/master

Add ability to use data ids in label formatting on pie chart slices
Reflect PR #599
Fix conflict
Merge branch 'michalkop93-dataOrder'
Update c3 API:
Added 'c3chart.data.axes' function, it works similar to 'c3chart.data.colors' and it allows to change the data Y axes dynamically.
Add tooltip ungrouping for multiple X. Fix #628.
Fix millisec date parsing - #607
Fix multiple click on step chart - #608
Add zoom API - #610
Support date for zoom API
Add 'shape-rendering: crispEdges' for step chart - #617
Fix edge of step chart on category axis - #566
Add zoom.rescale option to rescale y/y2 when zooming - #559
Fix targets is undefined in hasType - #618
Fix zoom - #598
Support multiple lines tick text on category axis - #139
Fix legend spec