Add stub to support packed pixel types.
Add unit tests for the packed pixel class.
Merge branch 'maint-simplify-implementation-of-color-module' into enh-add-packed-pixel-data-structure
Update 'CMakeLists.txt'.
Merge branch 'develop' into enh-add-packed-pixel-data-structure

Conflicts:
	test/Core/test_Defines.cpp
Add static array of integers for template meta-programming.
Renamed header file.
Fix header inclusion.
Update `CMakeLists.txt`.
Merge pull request #103 from DO-CV/enh-add-packed-pixel-data-structure

[ENH] Add packed pixel data structure.