function glorotNormal(args) {
	  return new GlorotNormal(args);
	}
Glorot normal initializer, also called Xavier normal initializer.
It draws samples from a truncated normal distribution centered on 0
with `stddev = sqrt(2 / (fan_in + fan_out))`
where `fan_in` is the number of input units in the weight tensor
and `fan_out` is the number of output units in the weight tensor.

Reference:
  Glorot & Bengio, AISTATS 2010
      http://jmlr.org/proceedings/papers/v9/glorot10a/glorot10a.pdf

@doc {heading: 'Initializers', namespace: 'initializers'}