use the right base class for all handlers

modules/user/views_handler_field_user_picture.inc

modules/user/views_handler_field_user_roles.inc

modules/user/views_handler_filter_user_current.inc

modules/user/views_handler_filter_user_name.inc

modules/user/views_handler_filter_user_permissions.inc

modules/user/views_handler_filter_user_roles.inc

modules/user/views_plugin_argument_default_current_user.inc

modules/user/views_plugin_argument_default_user.inc

modules/user/views_plugin_argument_validate_user.inc

modules/user/views_plugin_row_user_view.inc