Create checkpoint for ONNX.\n\nBefore this commit ONNX importer creat…

…ed input variables with batch axis.\n\nAfter this commit ONNX code moved on to using input variables without batch axis.

CNTK version 2.5.1 (Windows+Linux)

CNTK version 2.5 (Windows+Linux)

CNTK version 2.4 (Windows+Linux)

CNTK version 2.3.1 (Windows+Linux)

CNTK version 2.3 (Windows+Linux)

CNTK version 2.2 (Windows+Linux)

CNTK version 2.1 (Windows+Linux)

CNTK version 2.0 (Windows+Linux)

CNTK version 2.0 RC 3 (Windows+Linux)