Update highcharts.js directive

Allows for adding a highchart or a stockchart. Reads in options as json from the attributes of a chart and watched changes in the dataset.

<pre>
<highchart  value='{"series": [{"data": [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]}]}' 
                                        type="pie" 
                                        width="300" 
                                        height="200" 
                                        />

<highchart  value='{{marketSummary}}'
                            type='line'
                            width='600' 
                            height='400'  
                            chart='{"margin": [0, 0, 0, 0], "polar": true }'
                            colors='["#4572A7", "#AA4643", "#89A54E", "#80699B", "#3D96AE", "#DB843D", "#92A8CD", "#A47D7C", "#B5CA92"]'

                            title='{"text": "Browser market shares at a specific website, 2010"}'
                            xAxis='{"categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]}'
                            ></highchart>

<highstock
                                value='{{marketSummary}}'
                                type='candlestick'
                                width='600' 
                                height='400'
                                rangeSelector='{"selected":1}'
                                title='{"text": "Stock Chart"}'
                                series='[{"type":"candlestick", "name":"NAME HERE", "data":[]}]'
                                ></highstock>
</pre>