UI: add new button, top panel restyle etc

app/views/merge_requests/_head.html.haml

@@ -0,0 +1,12 @@
+.top-tabs
+  = link_to project_merge_requests_path(@project), :class => "tab #{'active' if current_page?(project_merge_requests_path(@project)) }" do 
+    %span 
+    Merge Requests  
+  
+
+  - if current_page?(project_merge_requests_path(@project))
+    - if can? current_user, :write_merge_request, @project
+      = link_to new_project_merge_request_path(@project), :class => "add_new", :title => "New Merge request", :remote => true do 
+        Add new
+
+

app/views/merge_requests/index.html.haml

@@ -1,7 +1,5 @@
-%h2.icon
-  %span>
-  Merge Requests
-.right= link_to 'New Merge request', new_project_merge_request_path(@project), :class => "grey-button"
+= render "merge_requests/head"
+
 - if @merge_requests.opened.count > 0
   %div{ :class => "update-data ui-box ui-box-small ui-box-big" }
     %h3
@@ -21,3 +19,9 @@
   .clear
   %br
 
+- unless @merge_requests.count > 0
+  .notice_holder
+    %li Merge Requests do not exist yet.
+    - if can? current_user, :write_merge_request, @project
+      %li You can add a new one by clicking on "Add New" button
+