We support splitting of a tensor along an axis into n pieces, where n
has to be a constant.
Eg:
  Split(Tensor of shape(5,30), splits=3, axis=1)
  returns 3 tensors of shape(5,10) each.

Currently we do not suport splitting into tensors of specified shape
(num_or_size_splits) though that functionality will be added later.

We also do not support splitting into n pieces where n is a runtime
value because we do not support run-time code generation yet.

This also adds support in the frontend for an op to return multiple
values.

We do this as a simplification on the tensorflow graph itself.
We transform SquaredDifference(a,b) into (a-b) * (a-b).

Remove the "" from attributes while parsing the graph def itself.
eg: "\"dtype\"" -> "dtype"
So we can directly refer to the attributes without adding double quotes to them.

* CrypTFlow2 code

* Some small corrections.

* Updated License to 2020

* Updated repo README to include SCI (CrypTFlow2) and moved CrypTFlow2/ to SCI/

Co-authored-by: Nishant Kumar <nishant.kr10@gmail.com>

* With new compiler changes

* After backend interface cleanup

* Interface cleaned up

* Removed funcSSCons and FLOAT_PRECISION fix

* funcSSCons right fix1

* Cleanup of several things ; Athos and EzPC changes for 2PC

* Residual changes

* More changes

* One left file