UBM-GMMs for 13 coefficients and deltas 0 and 1. It's still with errors.

Signed-off-by: Eduardo Tenorio <embatbr@gmail.com>
Refactoring code and adding more test images.

sigproc: OK
features: start from function 'mfcc'.
corpus: TODO
mixtures: TODO
main: TODO create code to identify a speaker
useful: update by demand

Signed-off-by: Eduardo Tenorio <embatbr@gmail.com>