Translation & secure-aware changes to studio's settings page

1. Change the link of course's about page secure aware, which displays 'https' or 'http' prefix according to the current protocol.
2. Make the email in this page translatable.

cms/templates/settings.html

@@ -7,6 +7,7 @@
 <%!
   from django.utils.translation import ugettext as _
   from contentstore import utils
+  import urllib
 %>
 
 <%block name="header_extras">
@@ -93,13 +94,26 @@ require(["domReady!", "jquery", "js/models/settings/course_details", "js/views/s
           <div class="note note-promotion note-promotion-courseURL has-actions">
             <h3 class="title">${_("Course Summary Page")} <span class="tip">${_("(for student enrollment and access)")}</span></h3>
             <div class="copy">
-              <p><a class="link-courseURL" rel="external" href="https:${lms_link_for_about_page}">https:${lms_link_for_about_page}</a></p>
+              <%
+                link_for_about_page = ("https:" if is_secure else "http:") + lms_link_for_about_page
+              %>
+              <p><a class="link-courseURL" rel="external" href="${link_for_about_page}">${link_for_about_page}</a></p>
             </div>
 
             <ul class="list-actions">
               <li class="action-item">
+                <%
+                  email_subject = urllib.quote(_("Enroll in {course_display_name}").format(
+                      course_display_name = context_course.display_name_with_default
+                  ).encode("utf-8"))
+                  email_body = urllib.quote(_('The course "{course_display_name}", provided by {platform_name}, is open for enrollment. Please navigate to this course at {link_for_about_page} to enroll.').format(
+                      course_display_name = context_course.display_name_with_default,
+                      platform_name = settings.PLATFORM_NAME,
+                      link_for_about_page = link_for_about_page
+                  ).encode("utf-8"))
+                %>
                 <a title="${_('Send a note to students via email')}"
-                    href="mailto:someone@domain.com?Subject=Enroll%20in%20${context_course.display_name_with_default}&body=The%20course%20&quot;${context_course.display_name_with_default}&quot;,%20provided%20by%20edX,%20is%20open%20for%20enrollment.%20Please%20navigate%20to%20this%20course%20at%20https:${lms_link_for_about_page}%20to%20enroll." class="action action-primary">
+                    href="mailto:someone@domain.com?Subject=${email_subject}&body=${email_body}" class="action action-primary">
                     <i class="icon-envelope-alt icon-inline"></i>${_("Invite your students")}</a>
               </li>
             </ul>