Mac OS X gui: Don't yield input more than needed. (End of the set of changes that makes quitting really fast.)

- Warn that WxWidgets is deprecated.
- Fix a few Wx error messages.

Comment out a few non-thread-safe functions from embedded vout
handling. Fixes a crash when playlist item changes. refs #955

* modules/codec/x264.c: Add support for multipass encoding. Slightly alter stats behaviour to reflect same usage as x264 cli (only one stats file). Needs testing..

should be increased. Fixes a few crashes when input changes.

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)