vstudio compilation
48khz was not obtained on windows.

now we continue with a different sample rate.

users can activate 48khz from the sound control panel:
 - control mmsys.cpl

(It's the mix format)

Should we tell them about it?
build script: verbose operation
-Wall -Wextra -Werror should go at the front of CFLAGS
clang on windows with vs2013