Fix some @param docs that have chars too close them.

Add `@property` annotations to `WP_User` and `WP_Post`.
Remove erroneous `@param`s from image editor class methods.
Officially add the property `$_column_headers` to `WP_List_Table`.	

See #30799.


git-svn-id: https://develop.svn.wordpress.org/trunk@31127 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-list-table.php

@@ -73,6 +73,13 @@ class WP_List_Table {
 	 */
 	protected $modes = array();
 
+	/**
+	 * Stores the value returned by ->get_column_info()
+	 *
+	 * @var array
+	 */
+	protected $_column_headers;
+
 	/**
 	 * Constructor.
 	 *