title: Formatting tooltip on Highchart (rCharts)
body: <p>I am looking for a way to format the date and number in a tooltip.</p>
  
  <p>By default, the formats in my example (see below) are:</p>
  
  <p>Date: "Monday, 27 Abr, 2015"
  Number: 1,999.265998</p>
  
  <p>Would like to change:
  Date: "27/04/2015, Monday"
  Number: 1.999,27</p>
  
  <p>Is it possible to apply this format for all Highcharts objects? (similar to <code>Highcharts.setOptions({lang})</code> in <a href="http://api.highcharts.com/highcharts#lang" rel="nofollow">JSON link</a>)</p>
  
  <p>Example:</p>
  
  <pre><code>require(rCharts)
  require(reshape2)
  
  test_data &lt;- data.frame("date0" = seq(Sys.Date()-14, Sys.Date(), by = 1),
                          "serie_1" = rnorm(15)+2000,
                          "serie_2" = rnorm(15)+2000
                          )
  test_data &lt;- melt(test_data, "date0")
  
  test_data["date"] &lt;-as.numeric(as.POSIXct(as.Date(test_data[["date0"]]), 
                                      origin="1970-01-01"))*1000
  
  my.hPlot &lt;- hPlot(x = "date", y = "value", group = 'variable', 
                    data = test_data, type = 'line')
  my.hPlot$xAxis(type = "datetime")
  my.hPlot$tooltip(shared = T, crosshairs = list(T, F))
  my.hPlot
  </code></pre>