Enable sidebar keyboard navigation on desktop touch computers

Fixes #112

assets/javascripts/views/sidebar/doc_list.coffee

@@ -17,7 +17,7 @@ class app.views.DocList extends app.View
     @lists = {}
 
     @addSubview @listSelect = new app.views.ListSelect @el
-    @addSubview @listFocus  = new app.views.ListFocus @el unless $.isTouchScreen()
+    @addSubview @listFocus  = new app.views.ListFocus @el unless app.isMobile()
     @addSubview @listFold   = new app.views.ListFold @el
 
     app.on 'ready', @render

assets/javascripts/views/sidebar/results.coffee

@@ -13,7 +13,7 @@ class app.views.Results extends app.View
 
   init: ->
     @addSubview @listSelect = new app.views.ListSelect @el
-    @addSubview @listFocus  = new app.views.ListFocus @el unless $.isTouchScreen()
+    @addSubview @listFocus  = new app.views.ListFocus @el unless app.isMobile()
 
     @search
       .on 'results', @onResults