Restructure content and linechart templates

Add some documentation to LineChart
Add TemplateMix to discreteBarChart

Add template for stackedareachart
Add the TemplateMix to base chart module
Add structure to discreteBarChart template
add ignore for vim swap files
Add mixin to CumulativeLineChart
Add TemplateMixin to linePlusBarChart

Clean all methods
Add template mixin to LinePlusBarWithFocusChart
Add template mixin to LineWithFocusChart