Alex Turbov authored Apr 29, 2018 and Craig Scott committed May 03, 2018

* Introduce `CMAKE_PROJECT_VERSION` and the corresponsing components:
  `CMAKE_PROJECT_VERSION_MAJOR`, `CMAKE_PROJECT_VERSION_MINOR`,
  `CMAKE_PROJECT_VERSION_PATCH` and `CMAKE_PROJECT_VERSION_TWEAK`.

* `CPack` module use `CMAKE_PROJECT_VERSION_MAJOR`,
  `CMAKE_PROJECT_VERSION_MINOR` and `CMAKE_PROJECT_VERSION_PATCH`
  to initialize corresponsing CPack variables.