Merge branch 'gradientdescent' of github.com:MatthieuBizien/neural_networks into gradientdescent

Conflicts:
	src/app/gradientdescent.h
Madssive reformating; now header only lib
Merge branch 'gradientdescent' of github.com:MatthieuBizien/neural_networks into gradientdescent

Conflicts:
	src/app/acostfunctionminimizeur.h