New UI for explore groups and trending pages

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/views/explore/groups/index.html.haml

 - page_title "Groups"
 - if current_user
   = render 'dashboard/groups_head'
-.clearfix.append-bottom-10
+.gray-content-block.clearfix
   .pull-left
     = form_tag explore_groups_path, method: :get, class: 'form-inline form-tiny' do |f|
       = hidden_field_tag :sort, @sort
       .form-group
         = search_field_tag :search, params[:search], placeholder: "Filter by name", class: "form-control search-text-input", id: "groups_search"
       .form-group
-        = button_tag 'Search', class: "btn btn-primary wide"
+        = button_tag 'Search', class: "btn btn-default"
   .pull-right
     .dropdown.inline
@@ -30,7 +30,7 @@
           = link_to explore_groups_path(sort: sort_value_oldest_updated) do
             = sort_title_oldest_updated
-%ul.bordered-list
+%ul.content-list
   - @groups.each do |group|
     = render 'shared/groups/group', group: group
   - unless @groups.present?

app/views/explore/projects/trending.html.haml

 - page_title "Trending Projects"
 - if current_user
   = render 'dashboard/projects_head'
-.explore-title
+
+.gray-content-block.explore-title
   %h3
     Explore GitLab
   %p.lead
     Discover projects and groups. Share your projects with others
-%hr
 .explore-trending-block
   .lead
     %i.fa.fa-comments-o

app/views/shared/groups/_group.html.haml

@@ -5,11 +5,9 @@
       - if can?(current_user, :admin_group, group)
         = link_to edit_group_path(group), class: "btn-sm btn btn-grouped" do
           %i.fa.fa-cogs
-          Settings
       = link_to leave_group_group_members_path(group), data: { confirm: leave_group_message(group.name) }, method: :delete, class: "btn-sm btn btn-grouped", title: 'Leave this group' do
         %i.fa.fa-sign-out
-        Leave
   = image_tag group_icon(group), class: "avatar s48 hidden-xs"
   = link_to group, class: 'group-name' do
@@ -17,7 +15,7 @@
   - if group_member
     as
-    %strong #{group_member.human_access}
+    %span #{group_member.human_access}
   %div.light
     #{pluralize(group.projects.count, "project")}, #{pluralize(group.users.count, "user")}