- This reflects modern CMake style, and also provides a measure of
protection against missing find_package() imports in downstream
clients resulting in linker errors when 'ceres' matches the compiled
library and not the imported target.
- The original 'ceres' target remains, as a local imported interface
target created by CeresConfig for backwards compatibility.
Change-Id: Ie9ed8de9b7059bc0cae1ae5002bb94d8fe617188