Much faster scheduling version.

Only main_jit.cpp changed at this commit.

Refer to main_jit.cpp to see quick performance notes.

This commit finished better scheduling at the stage of finding out
adaptive wiener filter parameters.

Also, I test all compute_root scheduling. This is fastest scheduling,
but need largest memory. Another not-bad scheduling at the stage of
finding adaptive wiener filter parameters is done. But I commented them
out for testing all compute_root.