Improve display of user block timestamps

Display the creation time, as a friendly date with a tooltip for
the exact time, and add a tooltip to the expiry time.

Fixes #923 and #996

app/helpers/user_blocks_helper.rb

@@ -7,14 +7,14 @@ module UserBlocksHelper
       if block.needs_view?
         I18n.t("user_block.helper.until_login")
       else
-        I18n.t("user_block.helper.time_future", :time => distance_of_time_in_words_to_now(block.ends_at))
+        I18n.t("user_block.helper.time_future", :time => friendly_date(block.ends_at)).html_safe
       end
     else
       # the max of the last update time or the ends_at time is when this block finished
       # either because the user viewed the block (updated_at) or it expired or was
       # revoked (ends_at)
       last_time = [block.ends_at, block.updated_at].max
-      I18n.t("user_block.helper.time_past", :time => distance_of_time_in_words_to_now(last_time))
+      I18n.t("user_block.helper.time_past", :time => friendly_date(last_time)).html_safe
     end
   end
 end

app/views/user_blocks/show.html.erb

@@ -30,6 +30,8 @@
 </p>
 <% end %>
 
+<p><b><%= t'user_block.show.created' %></b>: <%= raw t'user_block.show.ago', :time => friendly_date(@user_block.created_at) %></p>
+
 <p><b><%= t'user_block.show.status' %></b>: <%= block_status(@user_block) %></p>
 
 <p><b><%= t'user_block.show.reason' %></b></p>

config/locales/en.yml

@@ -2112,6 +2112,8 @@ en:
       heading: "%{block_on} blocked by %{block_by}"
       time_future: "Ends in %{time}"
       time_past: "Ended %{time} ago"
+      created: "Created"
+      ago: "%{time} ago"
       status: "Status"
       show: "Show"
       edit: "Edit"