Update gradient decent and Neural net to accept new activation functions.

test_GD and test_1d are giving good output.
test_regression has been added, which is supposed to fit a curve, however it is not yet working.

Merge branch 'master' of 192.168.1.5:~/programming/nnet

Conflicts:
	NNet.hpp
	gradient_decent.hpp
	test_simple2.cpp
Pulled out some unnecissary features

Removed the augmented Feed generating class.

Removed the predict_with_saved_input function which would store the pre-activation inputs for each node in an auxiliary feed while computing the activations..

Moved test_GD to test_xor, since it tests an XOR pattern
Moved test_regression to test_sin, since it tests a sin pattern, and is only working on a discretized sin wave in any case.
Added an image, which I hope I can get into the README