changed B back to NxK instead of KxN...
better c extension

- renamed opitimize to BaumWelch, because its the Baum-Welch algorithm.
- split c extension into more functions
- made c extension cleaner by seperating the api from the math. could
  even think about fortran now
- did some testing. many things have to be adjusted now probably.
- big data isnt handled well yet