Various fixes and improvements from feedback on multi-headed net testing:
Several important fixes to core components re. duplicate VIPs and execution of nodes whose input is also a graph output, as well as to generic partitioning (eliminate duplicate VIPs)
More data layout variants and a new MakeInputChanLast transformation to convert convnets to channels-last input
More high-level/identity-behavior layers supported in datatype inference
Various fixes and improvements from feedback on multi-headed net testing:
MakeInputChanLasttransformation to convert convnets to channels-last input