Merge branch 'master' of https://github.com/mikach/morris.js

Conflicts:
	morris.min.js

lib/morris.hover.coffee

@@ -11,9 +11,12 @@ class Morris.Hover
     @options.parent.append(@el)
 
   update: (html, x, y) ->
-    @html(html)
-    @show()
-    @moveTo(x, y)
+    if not html
+      @hide()
+    else
+      @html(html)
+      @show()
+      @moveTo(x, y)
 
   html: (content) ->
     @el.html(content)

morris.js

@@ -663,9 +663,13 @@ Licensed under the BSD-2-Clause License.
     }
 
     Hover.prototype.update = function(html, x, y) {
-      this.html(html);
-      this.show();
-      return this.moveTo(x, y);
+      if (!html) {
+        return this.hide();
+      } else {
+        this.html(html);
+        this.show();
+        return this.moveTo(x, y);
+      }
     };
 
     Hover.prototype.html = function(content) {