better handle when there is no margin top / bottom

Author: zamiang

dist/jquery.poplockit.js

@@ -40,6 +40,9 @@
         Column.__super__.constructor.call(this, $el, settings);
         this.$el = $el;
         this.settings = settings;
+        this.marginTop = 0;
+        this.marginBottom = 0;
+        this.marginLeft = 0;
         this.setDimensions(settings.height, settings.marginTop, settings.marginBottom, settings.marginLeft);
         this;
 

dist/jquery.poplockit.min.js

@@ -36,6 +36,12 @@
       super($el, settings)
       @$el = $el
       @settings = settings
+
+      # defaults
+      @marginTop = 0
+      @marginBottom = 0
+      @marginLeft = 0
+
       @setDimensions settings.height, settings.marginTop, settings.marginBottom, settings.marginLeft
       @