add support for plugins adding API methods

plugins/example_api/init.php

@@ -0,0 +1,31 @@
+<?php
+class Example_Api extends Plugin {
+
+	// Demonstrates adding a method to the API
+	// Plugin methods return an array containint
+	// 1. status (STATUS_OK or STATUS_ERR)
+	// 2. arbitrary payload
+
+	private $link;
+	private $host;
+
+	function about() {
+		return array(1.0,
+			"Example plugin adding an API method",
+			"fox",
+			true,
+			"http://tt-rss.org/");
+	}
+
+	function init($host) {
+		$this->link = $host->get_link();
+		$this->host = $host;
+
+		$host->add_api_method("example_testmethod", $this);
+	}
+
+	function example_testmethod() {
+		return array(API::STATUS_OK, array("current_time" => time()));
+	}
+}
+?>