Cleaning nn ui
Merge branch 'master' into nn2

Conflicts:
	src/test/java/water/Sandbox.java
NN fixes & allow other types of output layers
Merge branch 'nn2' into grids

Conflicts:
	src/main/java/hex/KMeans2.java
	src/main/java/hex/Layer.java
	src/main/java/hex/NeuralNet.java
	src/main/java/hex/Trainer.java
	src/main/java/water/Model.java
Progress on unified grid search && merged NN work