* First compiling pass, doesn't link tests, looks like templates aren't properly initialized?

* Make reduce inline, compiles, sum passes test

* Initial working reduce op builder

* Add Std dev, Variance, L2Norm. Tests fail because Power isn't actually implemented in ngraph++ yet

* Add Doc Strings, slight refactor

* fix tests after master merge

* Fix style issues raised in PR review

* Switch to Sum-based ops instead of Reduce-based ops for simpler autodiff.

* Add requested TODO comments

* Use all_close for tests

* Remove product op

cuDNN cmake boilerplate and helloworld gtest

* add json lib 2.1.1

* turn off clang-format for json lib

* add unit test file

* add code to poison the use of ngraph.hpp from within the ngraph library

* ParameterizedTensorView and ElementType cleanup

* change element to_type() to from()

CPU: Define ownerships and lifetimes for all entities

compute temporary memory pool size per function

Bob/simple function call

Bob/bool

Clang cuda example from:
https://gist.github.com/anonymous/855e277884eb6b388cd2f00d956c2fd4

Reused from Caffe 2 (Apache Licensed)

[Link](https://github.com/caffe2/caffe2/blob/master/cmake/Modules/FindCuDNN.cmake)

Toggle with -DUSE_CUDA=True flag

Bob/pch

CPU: Fix float32 literal emission