CC-3959: Make default username "source" for master and show inputs

-done (just added tooltip)

airtime_mvc/application/views/scripts/form/add-show-live-stream.phtml

@@ -21,6 +21,7 @@
         <div id="custom_auth_div">
             <dt id="custom_username-label" class="block-display">
                 <label class="optional" for="custom_username"><?php echo $this->element->getElement('custom_username')->getLabel() ?> :
+                <span class='stream_username_help_icon'></span>
                 </label>
             </dt>
             <dd id="custom_username-element" class="block-display">

airtime_mvc/application/views/scripts/form/preferences_livestream.phtml

@@ -33,6 +33,7 @@
         </dd>
         <dt id="master_username-label">
             <label class="optional" for="master_username"><?php echo $this->element->getElement('master_username')->getLabel() ?> :
+            <span class='stream_username_help_icon'></span>
             </label>
         </dt>
         <dd id="master_username-element">

airtime_mvc/application/views/scripts/form/stream-setting-form.phtml

@@ -68,7 +68,9 @@
                 </legend>
                 <dl class="zend_form">
                 <dt id="outputUser-label">
-                    <label for="outputUser"><?php echo $this->element->getElement('user')->getLabel()?> :</label>
+                    <label for="outputUser"><?php echo $this->element->getElement('user')->getLabel()?> :
+                    <span class='stream_username_help_icon'></span>
+                    </label>
                 </dt>
                 <dd id="outputUser-element">
                     <?php echo $this->element->getElement('user')?>