Mac OS X gui: Make sure libvlc exit properly. Don't forward the closeVout: if the interface is dead.

* modules/codec/x264.c: Revert [16936] (temporarily fix x264 encoding on darwin/x86 by disabling all CPU optimisations) as this shouldn't be a problem anymore..

Mac OS X gui: Fix a double unlock issue, by making sure all timers are disabled when checking if we have to unlock. (Pointed by Felix Paul Kuhne)

* fixed support for future darwin releases on Intel. SDL, goom, gnutls and libpng still need to be fixed on both platforms.

- Fix illegal error return value for getnaminfo from [18812]
- Do not crash if the APIs are not available (*NULL) from [18812]

Should fix most Win32 resolution crashes
(if not already done in previous commits)

Mac OS X gui: Use a recursive lock to be able to trigger enter/leaveFullscreen in the middle of an enter/leaveFullscreen operation.

This is bound to crash.

Close the embedded window only when playlist stop. Have the window to animate smoothly when size changes. Make the fullscreen mode behaves well when input changes and ends.