pluginhost: mention that update task & housekeeping hooks are for global plugins only

classes/pluginhost.php

@@ -15,13 +15,16 @@ class PluginHost {
 
 	const API_VERSION = 2;
 
+	// Hooks marked with *1 are run in global context and available
+	// to plugins loaded in config.php only
+
 	const HOOK_ARTICLE_BUTTON = 1;
 	const HOOK_ARTICLE_FILTER = 2;
 	const HOOK_PREFS_TAB = 3;
 	const HOOK_PREFS_TAB_SECTION = 4;
 	const HOOK_PREFS_TABS = 5;
 	const HOOK_FEED_PARSED = 6;
-	const HOOK_UPDATE_TASK = 7;
+	const HOOK_UPDATE_TASK = 7; // *1
 	const HOOK_AUTH_USER = 8;
 	const HOOK_HOTKEY_MAP = 9;
 	const HOOK_RENDER_ARTICLE = 10;
@@ -38,7 +41,7 @@ class PluginHost {
 	const HOOK_PREFS_SAVE_FEED = 21;
 	const HOOK_FETCH_FEED = 22;
 	const HOOK_QUERY_HEADLINES = 23;
-	const HOOK_HOUSE_KEEPING = 24;
+	const HOOK_HOUSE_KEEPING = 24; // *1
 	const HOOK_SEARCH = 25;
 	const HOOK_FORMAT_ENCLOSURES = 26;
 	const HOOK_SUBSCRIBE_FEED = 27;