Define a cmake function copy_files_to_build_dir(source_files,
targetsuffix) that defines a single custom target and single custom
command to copy the set of source files to
CMAKE_CURRENT_BINARY_DIR. All of the real work is done via cmake -E
copy_if_different.
This function will replace the nearly identical cmake code in several
other directories. This function has the advantage of being a single
target for the set of source files instead of a target per-file.
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
