[tensorflow] add new port for linux (#7568)

2019-08-20T19:13:26+00:00

* [+] Add tensorflow-cc port (Linux only)

* [~] Refactor installation of tensorflow/external

  1. Install tensorflow/external to tensorflow-etc/external;
  2. Fix TensorflowCCConfig.cmake accordingly.

* [tensorflow] Work in progress

* fix tensorflow linux config

* [tensorflow] partial support for windows

* fix config paths

* use environmental variables instead

* remove files

* add python_path

* add verbose error messages

* review fixes

* [tensorflow] refactor config file

* minor changes

* set arch for CI

vcpkg/ports/tensorflow-cc/TensorflowCCConfig.cmake, branch 2020.04

[tensorflow] add new port for linux (#7568)