permute_ and reshape_ return none

[hunghaoti]

Function 'permute_' and 'reshape_' return None. For example:

A = cytnx.ones([2,3])
B = A.permute_(1,0)
print(B) #None

A = cytnx.UniTensor.ones([2,3])
B = A.permute_([1,0])
print(B) #None

[pcchen]

I think the in-place version returns None is proper?

[IvanaGyro]

The behaviour was changed after #478.