Enable out-of-range group action configuration

[wismill]

In #487 I added keymap compile flags to configure the out-of-range group action, but it should be separate PR. Now I am also not sure the flags are the best API for this, so I added the following:

• xkb_keymap_set_out_of_range_layout_redirect
• xkb_keymap_set_out_of_range_layout_clamp

I have not added a function for the wrap action because it is the default, but we may need it for completion.

Another question is if it’s better to add only one function and expose xkb_range_exceed_type?

TODO:

• Changelog entry

[bluetech]

I haven't looked into the actual details, but just a general comment -- up to now xkb_keymap is an immutable type (well, at least except for the refcnt), which I think is a nice and useful property. Therefore I think it would be preferable if these settings were specified on keymap creation rather than after the fact.

[wismill]

Closing in favor of #507