doc addition about modifying @ISA after extends

Feel free to modify but I thought I would submit a suggestion at least.  Basically, the problem is seen when you have code that modifies the class' @ISA after an 'extends' call.  For instance, in DBIx::Class:

    package My::Schema::Result::SomeTable;
    use Moose;
    use MooseX::NonMoose;
    extends 'DBIx::Class::Core';
    __PACKAGE__->load_components('SomeComponentThatOverridesNew'); # modifies @ISA

    # later
    My::Schema::Result::SomeTable->new({}); # never calls SomeComponentThatOverridesNew::new()

MX::NonMoose grabs the nearest new() method at "extends" time so any other "new" methods prepended to the @ISA chain would be ignored.