complete rewrite of the update ext (again)

much cleaner than previous version
affixed the [beta] tag since this still has a few issues (mainly error checking/displaying etc.)

ext/update/theme.php

@@ -0,0 +1,14 @@
+<?php
+class UpdateTheme extends Themelet {
+	public function display_admin_block(){
+		global $page, $config;
+
+		$html = "".
+			"<b>Current Commit</b>: ".$config->get_string('commit_hash')." | (".$config->get_string('update_time').")".
+			"<br><b>Latest Commit</b>: <span id='updatecheck'>Loading...</span>".
+			"<br><a href='" . make_link('update/download') . "' id='updatelink'></a>";
+		//TODO: Show warning before use.
+		$page->add_block(new Block("Software Update", $html, "main", 75));
+	}
+}
+?>