It works now for sin function.

Started numpy extension based on sleef library:
http://freecode.com/projects/sleef
The basic avx-optimized sin ufunc is working now and is much faster, than
stok numpy function.
Rename avxsin to sin in avxmath module. Simple benchmark is written.
Rewritten alhorighm supposing that data step in numpy array will be equal to element size.
Module and benchmark are rewritten to support multiple functions. Added cos and exp.
Added sincos function for simultaious sine and cosine calculation
Added copyright and license notice.