Fix in reading data from file.

SIMD version crashes on big (>1M samples) files, investigating that.
Fixes in data read, cabal file and main driver.

Main driver mostly freed from (unneccessary) logging. It is commented out and can be enabled back.

Data read now has proper arguments in mapping and protection flags. It is necessary to have MAP_PRIVATE, otherwise nothing works.

Also there were troubles related to non-block aligned offset and length. Please note that reads should be block (4096 bytes) aligned and length should be block (4096 bytes) aligned too.

Cabal file now respects explicit language specification requirement.