Generalized Settings Pane Function

Settings panes can now be made just by adding an 'add_meta_box()'
function in the following format:

add_meta_box( 'wpmove-NAME-settings', __( 'NAME Settings', 'WPMove' ),
array($this, 'metabox_settings'), 'wpmove-settings',$context =
'advanced', $priority = 'default', $callback_args='NAME');