* Autodiff for abs

* Formatting, more tests for abs

* Cos autodiff; also a clarifying comment in the abs test

* Forgot cos.cpp

* Sin autodiff

* Again, forgot to add sin.cpp  :/

* Tan autodiff

* Minor formatting tweak

* Commit partial work on select backprop so I can run valgrind on the server  :/

* Fix boolean thingy so it works on Linux

* Autodiff for ceiling, convert (untested), floor, sign. Fix unit test for tan. Implement ceiling, floor in VM.

* Fix bug in abs/sign unit test ranges

* Add multiplicative inverse and square-root ops (needed for hyperbolic trig autodiff)

* Better formula for sqrt adjoints

* Autodiff for hyperbolic trig ops

* Forgot to add cpp files for hyperbolics

* Remove inv (don't need it after all); also formatting (oops)

* fix bug with Convert autodiff

* Autodiff for concat

* Restore the accidentally-commented-out unit test for abs

* Formatting

* Fix 'unordered_map.at' exception when Adjoints::Adjoints visit a node that has never been add_delta'd; remove workarounds for that bug

* Fix erroneous 'not implemented' docstring for op::Not

* Autodiff for sum

* Checking in broken support for replace_slice so I can test it with valgrind on the dev box

* Fix unit test bug with tensor initialization; formatting

* Implement replace-slice in CPU backend

* Autodiff for Slice and ReplaceSlice

* Tweak docs for ReplaceSlice

* Remove no-longer-needed cast of arg list to runtime::TensorView

* Start of pattern matcher

recursive graph matcher, pattern node

add matcher.cpp

add files for matcher, graph_rewrite

add const to on_match_class

fix comp errors

reshuffle pattern matching code across corresponding files

fix comment

run clang-format

graph_rewrite replace_node

getting simple test cases to work

op/pattern.cpp

toward graph_rewrite tests

older matcher API

before clean up tests

before rebase

build bbrks

more tests

clean up

more clean-up

more cleanup 2

more clean up 3

clean up 4

clang errors

clang errors2

apply code format

move match_class to matcher

major clean up after moving match_class to matcher.cpp

removing tracing changes

rebased as of 11/8

make matcher use i/o descs to traverse the graph; change replace_io

switching to io tds

graph_rewrite tests fail

all tests pass

formatting

unhandle outputs explicitly for now

reset permissions back to 0644; bad bad windows

fixes after rebase

* fixes

* addressing Scott's feedback

* Problem: Compile error on Mac with gcc 7.2
Solution: Should include <functional> to use std::function.

* Sort include names in alphabetical order.

* 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