Merge topic 'better_static_link_flags_docs'

6b17d85873 Help: Document when LINK_FLAGS and STATIC_LIBRARY_FLAGS are used
9561d42f95 target_link_options: Add test to verify static library behavior

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Robert Maynard <robert.maynard@kitware.com>
Merge-request: !2274