vlc_threads: provide proper implementation of vlc_spinlock or WIN32 (Windows 2000 required), avoid runtime assert

use intf_UserFatal when an error occurs while verifying the binary

update: put pgp key in its own header (and update the key to 2008), put a FIXME for some bug discovered (some signatures are smaller than 65 bytes), be more verbose when a problem happens.

Use big endian definitions for ffmpeg PIX_FMT_* when running on big endian machines. Eg: PIX_FMT_RGB24 should become PIX_FMT_BGR24.

set volume-change variable also in volumeUp/volumeDown, because it seemed that when you change volume with that, it wasn't setted

better now, thanks for j-b for spotting.

The Windows only code doesn't exist yet, but soon ?

This is so that the net_* functions can use it without making pushing locking assumption on their caller.