[MERGE] Add Hooks.install_named_hook

[Ian Clatworthy]

Daniel Mark Watkins wrote:
> On Wed, 02 Apr 2008 09:32:05 +0300
> Alexander Belchenko <bialix at ukr.net> wrote:
>> Your patch does not pass tests. Please rework it and update it for
>> 1.4 release.
> Done.
> 

I'll merge this tomorrow.

bb:tweak

> +    def test_install_named_hook_raises_unknown_hook(self):
> +        hooks = Hooks()
> +        hooks['set_rh'] = []
> +        self.assertRaises(UnknownHook, hooks.install_named_hook, 'silly',
> +                          None, "")

I don't think the hooks['set_rh'] line is needed here. Also the 1.4 vs
1.5 deprecation symbols (as abentley mentioned) need tweaking. Otherwise
good.

Ian C.