* infra for algebraic simplification and simplifications for Add and Multiply (including broadcast consts)

* add tests, fix bugs

* negative tests, 0*0, 0*1, 0+0

* possible fix for 0*1

* remove stale test

* fix merge comp errors

* fix comp errors

* get all ops working

* enable autodiff tests for IE backend

* Add logical-and, logical-or ops

* Restore accidentally-deleted test

* add new ops to IE backend

* Enable users to request default/row-major layouts on result nodes

* copy default layout attribute when copying the result ops

* Result nodes cannot be replaced. use direct graph manipulation instead

* Add unit test to verify default layouts on result nodes when requested

* any -> skip

* run style check

* add CUDNN_SAFE_CALL and CUBLAS_SAFE_CALL

* using sstream

* passed all unit test

* format error msg

* fix ( ) bug

* fix convolution bug by retain primary context for device
* add release to destructor

* ie backend and manager with passing unit tests except for select/function

* fix function_call and select

* simplify implemenation by removing support for convert and select

* remove manager

This better supports non-ubuntu/debian systems.

* Support Concat with mkldnn (two inputs)

* Support concat with mkldnn (multiple inputs)

* Address feedback

* Remove unused variable

* Allow rank two tensor to mkldnn for concat & add a test case for 2D inputs

* Add mkldnn_any layout to concat

* Make API changes to get consistent with master

executables not shared libraries. This change will remove the following
warning.
ld: warning: -pie being ignored. It is only used when linking a main executable

Force test to fail if any env fails.

* Move runtime::Manager functionality into runtime::Backend

* Remove unused files

* remove obsolete function

* remove obsolete classes

* Remove usage of CMAKE_MAKE_PROGRAM as it slows down parallel build

* Make make properly propagate to child and add back targeted build.

* Revert "Make make properly propagate to child and add back targeted build."

This reverts commit b4b1d8db0f0d42850e53d4e0f773261c292ccaf6.

* * cuda_emitter::build_pad now utilizes pad_value.

* Added TypeInfo class for dispatching c-type information from the underlying ngraph element::Type.
  Adjusted test to use all_close when comparing floating point values (max_pool_2d_1channel_1image_overpadded).

* Refactored max_pool_1d into cuda_emitter so that numeric_limits<c_type>::lowest() could be used for initial max value.
Test max_pool_2d_1channel_1image_padded_negative_values now enabled and passes.

* Removed old function and switch to size_t to match ngraph.

* Added virtual dtor.

* Adding support for interior padding. All op::Pad functionality is now included.

* More info in runtime_error for checking of tensor dimensions. Removed commented code.

* CPU weight fusion initial version

* add tests for weight_fusion

* address @jbobba's feedback

* before cleaning up convolution_weight_optimization.cpp

* clean up, rename, fix perms, fix format

* reenable unit test

- Set default input axes order.

* remove tensor_call from backends

* remove obsolete methods

* CMake: Allow build target arch to be overridden

* Add DNGRAPH_TARGET_ARCH option to install docs

* get_input_op -> get_argument

* more replacing

* more replacing2

* Update default paths in setup.py

* Update defaults arguments in tox

* remove obsolete

* change to use new Backend API

* rename parameter

* remove deprecated

* remove all legacy Backend API usage

remove deprecated files

* pull in changes from master

* fix GPU calls

* disable tests in convolution generator

* update per PR comments. Enable performance counter feature.

* update per PR comments

* fix build error

* fix conditionally compiled test :(

* BatchNorm documentation

* Fix typo, install URL

* Switch to desired BatchNorm

fixed variable settings in contrib/docker/make-dimage.sh script

* Add python wrapper for nGraph Reduce operation.

- Add UT.

* Refactoring.

- Add UT case with default reduction on all axes.

* Extend `reduce` operation signature to also accept `Function` object.

- Add UT case.

* Fix formatting errors.