Improved class styling for nodes

Added unit testing
classDefs are now exported to the common style of the SVG
Styling is no longer copied from other mermaid SVGs on the same webpage

src/diagrams/flowchart/flowRenderer.js

@@ -37,7 +37,7 @@ exports.addVertices = function (vert, g) {
          * @type {string}
          */
         var classStr = '';
-        
+
         if(vertice.classes.length >0){
             classStr = vertice.classes.join(" ");
         }
@@ -138,11 +138,34 @@ exports.addEdges = function (edges, g) {
 };
 
 /**
- * Returns the default style for nodes.
- * @returns {string} Default style for nodes
+ * Returns the all the styles from classDef statements in the graph definition.
+ * @returns {object} classDef styles
  */
-exports.defaultNodeStyle = function () {
-    return ".node {fill:#eaeaea; stroke:#666; stroke-width:1.5px;}";
+exports.getClasses = function (text, isDot) {
+    var parser;
+    graph.clear();
+    if(isDot){
+        parser = dot.parser;
+
+    }else{
+        parser = flow.parser;
+    }
+    parser.yy = graph;
+
+    // Parse the graph definition
+    parser.parse(text);
+
+    var classDefStylesObj = {};
+    var classDefStyleStr = '';
+
+    var classes = graph.getClasses();
+
+    // Add default class if undefined
+    if(typeof classes.default === 'undefined') {
+        classes.default = {id:'default'};
+        classes.default.styles = ['fill:#eaeaea','stroke:#666','stroke-width:1.5px'];
+    } 
+    return classes;
 };
 
 /**