Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Macbook [Pro] keyboards in AZERTY don't need shift to get to '~'.

MFC after: 3 days

Add a Macbook/Macbook Pro compatible keyboard layout for French keyboards.
It is a latin9/ISO_8859-15 and features dead keys for ^/uml/`, Euro, oe/OE
support and a few additional characters like copyright/trademark.

It is probably Powerbook/iBook compatible but I don't have a machine to test
it with and the primary objective was to have a correct keyboard for within
Parallels (for IntelMacs).

Approved by: re (hrs)