only stop inline feed updates with open_basedir enabled if there are any plugins that require CURL enabled

add plugin->flags() returning array with additional plugin information, currently only CURL requirement (optional)

classes/plugin.php

@@ -15,6 +15,13 @@ class Plugin {
 		return array(1.0, "plugin", "No description", "No author", false);
 	}
 
+	function flags() {
+		/* associative array, possible keys:
+			needs_curl = boolean
+		*/
+		return array();
+	}
+
 	function get_js() {
 		return "";
 	}