merged feature/stateMgmt and canvas
Merge branch 'refactoring-pie-pieChart' into feature/stateMgmt
pie.js - labels, refactoring
multiBar & multiBarChart refactoring
multiBar & multiBarChart refactoring
Merge branch 'canvas' into multiBar-multiBarChart

Conflicts:
	src/models/pie/pie.js
refactoring
2 hot fixes
Merge branch 'canvas' into multiBar-multiBarChart
Added Layer::margin getter/setter.