dcadec: Decode LFE to avoid adding random data when downmixing with LFE

Signed-off-by: Tim Walker <tdskywalker@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
libvpx: do not mark VP9 as experimental when using libvpx >= 1.3.0

Signed-off-by: Diego Biurrun <diego@biurrun.de>
configure: Separate MinGW32 and MinGW64 libc handling
dsputil: Move apply_window_int16 to ac3dsp

The (optimized) functions are used nowhere else.
configure: Move adding of compat objects out of libc detection