help: missing #include
macosx: disable macosx-black by default

...because this option behaves awful in Mavericks.
macosx: enable native fullscreen by default on mavericks

This has the best integration and works without visual glitches around
the menu bar, with multiple monitors.
Revert "vda: user ref buffer mode"

This commit is not valid as the libav part is still missing.

This reverts commit c7a2a17a6d0b0f4c5c3e12fbe0dd12730d08c0f2.
macosx: rename macro for mavericks detection since its out now