Allow node labels to be left-justified with textAlign: 'left'

Will only apply to Network nodes with a shape: 'box' property, as most
other shapes this will not make sense for. This enables the box shape
to be used, for instance, for diagraming CFG data from source code.

lib/network/modules/NodesHandler.js

@@ -49,7 +49,8 @@ class NodesHandler {
         background: 'none',
         strokeWidth: 0, // px
         strokeColor: '#ffffff',
-        align: 'horizontal'
+        align: 'horizontal',
+        textAlign: 'center'
       },
       group: undefined,
       hidden: false,

lib/network/modules/components/shared/Label.js

@@ -127,7 +127,13 @@ class Label {
     // configure context for drawing the text
     ctx.font = (selected && this.nodeOptions.labelHighlightBold ? 'bold ' : '') + fontSize + "px " + this.fontOptions.face;
     ctx.fillStyle = fontColor;
-    ctx.textAlign = 'center';
+    // When the shape is a box and the textAlign property is 'left', make label left-justified
+    if (this.options.shape === 'box' && this.options.font.textAlign === 'left') {
+      ctx.textAlign = 'left';
+      x = x - (this.size.wideth >> 1); // Shift label 1/2-way (>>1 == div by 2) left
+    } else {
+      ctx.textAlign = 'center';
+    }
 
     // set the strokeWidth
     if (this.fontOptions.strokeWidth > 0) {