add toggle_sidebar plugin, remove obsolete toggle button

add PluginHost::HOOK_MAIN_TOOLBAR_BUTTON

plugins/toggle_sidebar/init.php

@@ -0,0 +1,34 @@
+<?php
+class Toggle_Sidebar extends Plugin {
+
+	private $host;
+
+	function about() {
+		return array(1.0,
+			"Adds a main toolbar button to toggle sidebar",
+			"fox");
+	}
+
+	function init($host) {
+		$this->host = $host;
+
+		$host->add_hook($host::HOOK_MAIN_TOOLBAR_BUTTON, $this);
+	}
+
+	function hook_main_toolbar_button() {
+		?>
+
+		<button dojoType="dijit.form.Button" onclick="collapse_feedlist()">
+			<img src="plugins/toggle_sidebar/application_side_list.png"
+				 title="<?php echo __('Collapse feedlist') ?>">
+		</button>
+
+		<?php
+	}
+
+	function api_version() {
+		return 2;
+	}
+
+}
+?>