made CPTableView aware of a resize in CPTableColumn

AppKit/CPTableColumn.j

@@ -377,6 +377,8 @@ CPTableColumnUserResizingMask   = 1 << 1;
 
 - (void)_postDidResizeNotificationWithOldWidth:(float)oldWidth
 {
+    [[self tableView] _didResizeTableColumn:self];
+
     [[CPNotificationCenter defaultCenter]
     postNotificationName:CPTableViewColumnDidResizeNotification
                   object:[self tableView]

AppKit/CPTableView.j

@@ -846,6 +846,11 @@ CPTableViewFirstColumnOnlyAutoresizingStyle = 5;
     return _tableColumns[index];
 }
 
+- (void)_didResizeTableColumn:(CPTableColumn)theColumn
+{
+    [self _autosave];
+}
+
 //Selecting Columns and Rows
 
 /*!