Module v0_9_0_rc2

Fixed

• Fixed crate level doc

Added

• Added changelog
• Associated function SessionBuilder::compression
• Associated function SessionBuilder::user_known_hosts_file
• Associated function Session::control_socket for non-Windows platform.

Changed

• Make ChildStdin an opaque type.
• Make ChildStdout an opaque type.
• Make ChildStderr an opaque type.

Removed

• Type Sftp.
• Type Mode.
• Type RemoteFile.
• Associated function Session::sftp.