s3interface is to handle all s3 restful api wrapper, like listBucket()
and fetchData(), s3restful is to handle HTTP GET, and PUT in future.

remove scripts directory.
remove LICENSE file since it's the same as GPDB's.
remove dead codes and meaningless comments.
reorder header includings alphabetically.
add a missing unit test for find_replace().
rename testing sql files.
rename source files.
optimize compiling flags.