Dynamic Time Warping

DTW implementation according to:
1) http://mirlab.org/jang/books/dcpr/dpDtw.asp?title=8-4%20Dynamic%20Time%20Warping
2) http://en.wikipedia.org/wiki/Dynamic_time_warping

Issues:
Type-2 results differ from 2)

Todos:
Implementing start boundary condition still outstanding
Correctness test outstanding