lineDataSymbol and lineDash per data set

[Jank1310]

Added an option to set different lineDataSymbols per data set.

Example

const PptxGenJS = require('./dist/pptxgen.js');
var pptx = new PptxGenJS();
var slide = pptx.addNewSlide();

// Chart Type: LINE
var dataChartAreaLine = [
  {
    name  : 'Actual Sales',
    labels: ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'],
    values: [1500, 4600, 5156, 3167, 8510, 8009, 6006, 7855, 12102, 12789, 10123, 15121]
  },
  {
    lineDataSymbol:'diamond',
    name  : 'Projected Sales',
    labels: ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'],
    values: [1000, 2600, 3456, 4567, 5010, 6009, 7006, 8855, 9102, 10789, 11123, 12121]
  }
];
slide.addChart( pptx.charts.LINE, dataChartAreaLine, { x:1.0, y:1.0, w:12, h:6, showLegend:true } );

pptx.save('Demo-Line-Chart');