put wiki templates back into Django templating

lms/templates/wiki/includes/cheatsheet.html

-<%! from django.utils.translation import ugettext as _ %>
+{% load i18n %}
 <div class="modal hide fade" id="cheatsheetModal">
 	<a href="#" class="close-btn">×</a>
 	<div id="cheatsheet-body" class="modal-body">
 		<div class="left-column">
 			<section>
-				<h2>${_("Wiki Syntax Help")}</h2>
-				<p>${_("This wiki uses <strong>Markdown</strong> for styling. There are several useful guides online. See any of the links below for in-depth details:")}</p>
+				<h2>{% trans "Wiki Syntax Help" %}</h2>
+				<p>{% trans "This wiki uses <strong>Markdown</strong> for styling. There are several useful guides online. See any of the links below for in-depth details:" %}</p>
 				<ul>
-					<li>${_('<a href="http://daringfireball.net/projects/markdown/basics" target="_blank">Markdown: Basics</a>')}</li>
-					<li>${_('<a href="http://greg.vario.us/doc/markdown.txt" target="_blank">Quick Markdown Syntax Guide</a>')}</li>
-					<li>${_('<a href="http://www.lowendtalk.com/discussion/6/miniature-markdown-guide" target="_blank">Miniature Markdown Guide</a>')}</li>
+					<li>{% trans '<a href="http://daringfireball.net/projects/markdown/basics" target="_blank">Markdown: Basics</a>' %}</li>
+					<li>{% trans '<a href="http://greg.vario.us/doc/markdown.txt" target="_blank">Quick Markdown Syntax Guide</a>' %}</li>
+					<li>{% trans '<a href="http://www.lowendtalk.com/discussion/6/miniature-markdown-guide" target="_blank">Miniature Markdown Guide</a>' %}</li>
 				</ul>
-				<p>${_("To create a new wiki article, create a link to it. Clicking the link gives you the creation page.")}</p>
-                                <pre>${_("[Article Name](wiki:ArticleName)")}</pre>
+				<p>{% trans "To create a new wiki article, create a link to it. Clicking the link gives you the creation page." %}</p>
+                                <pre>{% trans "[Article Name](wiki:ArticleName)" %}</pre>
 			</section>
 			<section>
-				<h3>${_("{edX} Additions:").format(edX="edX")}</h3>
+				{% comment %}
+					Translators: Do not translate "edX"
+				{% endcomment %}
+				<h3>{% trans "edX Additions:" %}</h3>
 				<pre>
 circuit-schematic:</pre>
 				<pre>
@@ -25,30 +28,34 @@ $LaTeX Math Expression$</pre>
 
 		<div class="right-column">
 			<section>
-				<h3>${_("Useful examples:")}</h3>
+				<h3>{% trans "Useful examples:" %}</h3>
 				<pre>
-${_("http://wikipedia.org\
-[{Wikipedia}](http://wikipedia.org)\
-[{edX} Wiki](wiki:/edx/)").format(edX="edX", Wikipedia="Wikipedia")}</pre>
+{% comment %}
+	Translators: Do not translate "edX" or "Wikipedia"
+{% endcomment %}
+{% trans "http://wikipedia.org" %}
+{% trans "[Wikipedia](http://wikipedia.org)" %}
+{% trans "[edX Wiki](wiki:/edx/)" %}
+				</pre>
 				<pre>
-${_("Huge Header")}
+{% trans "Huge Header" %}
 ===========</pre>
 				<pre>
-${_("Smaller Header")}
+{% trans "Smaller Header" %}
 --------------</pre>
 				<pre>
-${_("*emphasis* or _emphasis_")}</pre>
+{% trans "*emphasis* or _emphasis_" %}</pre>
 				<pre>
-${_("**strong** or __strong__")}</pre>
+{% trans "**strong** or __strong__" %}</pre>
 				<pre>
-${_("- Unordered List\
-	- Sub Item 1\
-        - Sub Item 2")}</pre>
+- {% trans "Unordered List" %}
+	- {% trans "Sub Item 1" %}
+    	- {% trans "Sub Item 2" %}</pre>
 				<pre>
-${_("1. Ordered\
-2. List")}</pre>
+1. {% trans "Ordered" %}
+2. {% trans "List" %}</pre>
 				<pre>
-${_("> Quotes")}</pre>
+> {% trans "Quotes" %}</pre>
 			</section>
 		</div>
 

lms/templates/wiki/includes/editor_widget.html

-<%! from django.utils.translation import ugettext as _ %>
+{% load i18n %}
 <textarea {{ attrs }}>{{ content }}</textarea>
 <p id="hint_id_content" class="help-block">
- ${_('Markdown syntax is allowed. See the <a id="cheatsheetLink" href="#">_{("cheatsheet")}</a> for help.')}
+	{% comment %}
+		Translators: Do not translate 'cheatsheetLink'
+	{% endcomment %}
+	{% trans "Markdown syntax is allowed. See the <a id='cheatsheetLink' href='#'>cheatsheet</a> for help." %}
 </p>

lms/templates/wiki/preview_inline.html

-<%! from django.utils.translation import ugettext as _ %>
 <!DOCTYPE html>
 {% load wiki_tags i18n %}{% load compressed %}
 <html>
@@ -29,8 +28,8 @@
 
       {% if revision and revision.deleted %}
         <div class="warning">
-          <strong>${_("This revision has been deleted.")}</strong> 
-          <p>${_("Restoring to this revision will mark the article as deleted.")}</p>
+          <strong>{% trans "This revision has been deleted." %}</strong> 
+          <p>{% trans "Restoring to this revision will mark the article as deleted." %}</p>
         </div>
       {% else %}
         {% wiki_render article content %}