actions: Move sender information out of the popover title into the body

This makes sense because the actions aren't really about the sender.

(imported from commit cf47939ecc93f4d1113268637e41c0a6daa0f2c2)

zephyr/jstemplates/actions_popover_content.html

@@ -1,6 +1,10 @@
 {{! Contents of the "message actions" popup }}
 <ul class="nav nav-list actions_popover">
   <div class="popover_info">
+    <li>Sent by <b>{{message.sender_full_name}}</b></li>
+    <li class='my_email'>{{message.sender_email}}</li>
+    <hr />
+
     <li>{{message.full_date_str}}</li>
     <li>{{message.full_time_str}}</li>
     <hr />

zephyr/jstemplates/actions_popover_title.html

@@ -1,8 +1,6 @@
 {{! Title of the "message actions" popup }}
-<span title="{{message.sender_full_name}}">
-  <b>{{message.sender_full_name}}</b>
-</span><br />
-
-<span class='my_email' title="{{message.sender_email}}">
-  {{message.sender_email}}
-</span>
+{{#if message.is_stream}}
+Message to stream <b>{{message.display_recipient}}</b>
+{{else}}
+Private message
+{{/if}}

zephyr/static/styles/zephyr.css

@@ -646,6 +646,7 @@ table.floating_recipient {
 .popover-title {
     overflow-x: hidden;
     text-overflow: ellipsis;
+    text-align: center;
 }
 
 .popover_info {