hevcdsp: correctly indicate that hevc_put_hevc_bi_epel_h uses 9 GPRs

Fixes FATE on Windows.

Reviewed-by: "Ronald S. Bultje" <rsbultje@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fix compilation with --enable-lto --enable-shared with icc.
Use Matroska document version 2 for WebM files if possible.

Google's plugin for the Internet Explorer refuses to play
files with another document version.

Fixes ticket #3583.