Known issue and fix in training

[tcies]

Symptom: Fails with exception https://github.com/uzh-rpg/imips_open/blob/master/train.py#L83 , many output channels are either all 0 or all 1.

Fix:
Replace

imips_open/python/imips/nets.py

Lines 90 to 95 in 9285a4f

	def inlierLoss(x):
	return -tf.log(x)
	def outlierLoss(x):
	return -tf.log(1 - x)

with

EPS = 10e-5

def inlierLoss(x):
    return -tf.log(x + EPS)


def outlierLoss(x):
    return -tf.log(tf.maximum(1 - x, EPS))

Thanks Logan Lembke from South Dakota School of Mines and Technology for the bug report and @Talasta for the fix!

I hope to get around to fix this with the appropriate testing.