Fix two bugs found by @TiuTalk

* When redirecting internal links, double-check that they actually
  are internal before doing so.
* Avoid double-adding items to the /browse mod list

src/coffee/controllers/base_controller.coffee

@@ -63,6 +63,9 @@ module.exports = class BaseController extends Backbone.View
         href = $(event.target).attr 'href'
         href ?= $(event.currentTarget).attr 'href'
         logger.info "Re-routing link to internal navigation: #{href}"
+        if href? and href.match /^http/
+            window.location.href = href
+
         router.navigate href, trigger:true
 
     show: (args...)->

src/coffee/controllers/browse_page_controller.coffee

@@ -45,6 +45,7 @@ module.exports = class BrowsePageController extends PageController
             controller = @_controllers[controllerIndex]
             if not controller?
                 controller = new ModController model:mod
+                @_controllers.push controller
                 controller.render()
                 @$modContainer.append controller.$el
             else

src/coffee/controllers/mod_pack_controller.coffee

@@ -68,5 +68,4 @@ module.exports = class ModPackController extends BaseController
                 index += 1
 
         while @_modControllers.length > index
-            controller = @_modControllers.pop()
-            controller.$el.fadeOut duration:Duration.normal, complete:-> @remove()
+            @_modControllers.pop().remove()