[SSHD-374] Nio2Acceptor never unbinding
[SSHD-375] Buffer.MAX_LEN and DefaultSftpClient#write() don't play well together
[SSHD-381] Wrong values used for SSH_FXP_OPEN flags
[SSHD-380] Refactor tests to let the system choose the port instead of using getFreePort() which can lead to problems
[SSHD-379] Require JDK 1.7
[SSHD-377] Create a nio FileSystem implementation for sftp
[SSHD-378] Switch to nio FileSystem api for commands (scp and sftp subsystem)
Sftp v4 partial support, better implementations in SftpFileSystemProvider
Sftp v5 server side
Add initial support for sftp v6
FileChannel implementation with locking
Fix inverted parameters for creating symbolic links
Allow forcing the use of a given sftp version on the server
Fix sftp version handling on the client side
Print flags in FSTAT/LSTAT