Revert "Fix displaying -0 in visual reports (#25)"

This reverts commit 3539a61.

It gets stringified in VM so we'll fix it in there instead.

Author: GarboMuffin

core/workspace_svg.js

@@ -1095,15 +1095,7 @@ Blockly.WorkspaceSvg.prototype.reportValue = function(id, value) {
   var contentDiv = Blockly.DropDownDiv.getContentDiv();
   var valueReportBox = goog.dom.createElement('div');
   valueReportBox.setAttribute('class', 'valueReportBox');
-
-  var valueAsString;
-  if (Object.is(value, -0)) {
-    valueAsString = '-0';
-  } else {
-    valueAsString = '' + value;
-  }
-  valueReportBox.textContent = valueAsString;
-
+  valueReportBox.textContent = value;
   contentDiv.appendChild(valueReportBox);
   Blockly.DropDownDiv.setColour(
       Blockly.Colours.valueReportBackground,