* Simplified & tightened all_close_f parameters

Removed specification of mantissa bits for all_close_f in favor
of just specifying tolerance bits. Tightened up all_close_f default.
Fixed LRN unit test which had insufficient result precision to pass
tighter all_close_f tolerance.

* Addressed PR comments.

Reworked mantissa bit and tolerance constants.
Clarified and improved graph comparison tolerance calculation flexibility.
Clarified unit test tolerance testing.

* update licenses for 2019

* style

* Simplified all_close_f tolerance determination. Made all_close_f less verbose. Transitioned graph comparison to use double comparison when appropriate.

* Reworked all_close_f AssertionResult returning code to include message in AssertionResult on success also.

* Added CMake option NGRAPH_GTEST_INFO, which controls whether or not any gtest info cout is done. Quiets all_close_f tests by default.

* Moved NGRAPH_GTEST_INFO from build option to environment variable.

* change all_close tests to return gtest AssertionResult instead of bool to allow for better error messages

* change throw to return error

* address PR comments and fix compile error

* Double support for all_close_f

* all_close_f uses fixed number of mantissa bits now. Simplified testing code.

* Initialize test data members in constructor to values which will cause test failure. Setup then sets them correctly.

* Reduce info printed out during all_close_f unit tests.

* Additional info calculated & printed for all_close_f.

* Fixed format

* Tweaked test calls to all_close_f to make unambiguous.

* Tweaked test calls to all_close_f to match close_f for last unit test.

* rename files

* rename runtime TensorView to Tensor

* rename HostTensorView to HostTensor

* use line comments instead of multiline comments for license header

* update more

* update new files

* more header updates

* style

* normalize doxygen keywords

* more normalization

* normalize more onnx files

* yet more normalization

* fix doxygen error