Added another buffer operation BufMixCoeff allowing to mix a certain
buffer to another at a given amount (coeff). CpuX86 has been extended
by an according SSE implementation.
The new CPU framework replaces the old BasicOps framework. It is more
flexible and the build process isn't such a mess anymore (pre-compiled
assembler files etc.). It will hopefully see some improvements and
extensions soon.
Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>