title: CasperJS/PhantomJS : waitForSelector('svg') -> svg sometimes doesn't appear
body: <p>So here another trouble. I have a script loading svg and waiting for it to appear which randomly fails. Sometimes phantom stay stuck loading svg (even with a <code>waitTimeout</code> at 2min, so the problem isn't here I think). script : <code>http:// r.ccmbg.com/js.php?m=highchart=...</code></p>
  
  <p>I could still load the page X times in a loop waiting for svg to appear, but I'd prefer another solution. If you have an idea, I'm all ears. </p>
  
  <p>Simple example :</p>
  
  <pre><code>casper.test.begin('\n********* Navigation on directories : ***********', 8,{
  setUp: function(test) {
      //setLevel("normal");
  },
  
  tearDown: function(test) {
      //getJSON();
  },
  
  test: function(test){
      "use strict";
      casper.start()
      .thenOpen('http://www.linternaute.com/voyage/climat/paris/ville-75056/2013-2008')
      .waitForResource(/m=highcharts&amp;/, function(){
          this.waitForSelector('svg',function(){
              this.test.assertExists("tspan");
          });
      })      
      .waitForUrl(/2008/, function(){
          this.test.assertSelectorHasText("h2", "maximales");
          this.test.assertSelectorHasText("h2", "minimales");
          this.test.assertSelectorHasText("h2", "Paris");
          this.test.assertSelectorHasText("h2", "Le soleil");
          this.test.assertSelectorHasText("h2", "La pluie");
          this.test.assertExists("div.marB20");
          this.test.assertNotEquals(this.fetchText("div.marB20 &gt; table &gt; thead &gt; tr &gt; th"), " ", "Table first data not empty");
      })
      .run(function() {
          this.test.comment('--- Done ---\n');
          test.done();
      });
  }
  });
  </code></pre>