Rename work some renaming of rename exclusion options and more docs
HADOOP-9361 specification review, especially rename()
HADOOP-9361 move name of file with test binding info from auth-keys.xml to test/resources/contract/test-options.xml . This is because it covers more than just auth details. Updated docs and .gitignore
HADOOP-10589 / HADOOP-10533: NPE in S3NativeInputStream if stream inited with a null pointer
HADOOP-9361 FTPFileSystem testing reveals bad close() deferencing if connection fails: make FTP and FSDataOutputStream more robust, add SHOULD refs in spec for "clean. robust teardown"