Implement call for shows feature

Add display_call_for_shows MACRO. Update index template to include
call to display_call_for_shows.

templates/shared-call_for_shows.tpl.html

@@ -0,0 +1,21 @@
+<!--% PROCESS 'shared-utils.tpl.html' %-->
+<!--% MACRO display_call_for_shows BLOCK %-->
+	<!--% query_call_for_shows = DBI.prepare('
+		SELECT CASE WHEN COUNT(id) < 7 THEN True ELSE False END AS `request_for_shows`
+		FROM eps
+		WHERE eps.date > date(\'now\') AND eps.date < date(\'now\', \'+10 days\')
+		')
+	%-->
+	<!--% results_call_for_shows = query_call_for_shows.execute().get_all() %-->
+		<!--% IF results_call_for_shows.0.request_for_shows == 1 %-->
+	<!--% USE date %-->
+	<article>
+		<header>
+			<h3>Call for shows</h3>
+		</header>
+		<p><strong><em>We are running very low on shows</em></strong> at the moment. Have a look at the <a href="<!--% absolute_path(baseurl) %-->correspondents/index.html">hosts</a> page and if you don't see "<!--% date.format(date.now, '%Y') %-->-??-??" next to your name, or if your name is not listed, you might consider sending us in something.</p>
+		<!--     <img src="/images/hprstats.png" alt="hpr queue showing an graph showing how few shows we have" /> -->
+		<p>There are no files to process on the FTP server.</p>
+	</article>
+	<!--% END %-->
+<!--% END %-->