v1.4.0

• FtpClient::fileSize fixed for servers that not support SIZE feature.
• FtpClient::listDir fixed compatibility issue with some FTP servers.
• Connection::isConnected fixed bug : if the connection is not established yet the method was returned
  a NULL value instead of false.
• FtpCommand::raw improved and added the end-message to the returned array.
• FtpClient::isDir performance optimized.
• FtpClient::listDirDetails improved (No Breaking Change).
• FtpClient::getFeatures is now returns false in failure.
• FtpClient::isFeatureSupported can now throw a FtpClientException exception.
• ConnectionInterface::isSecure is deprecated see #15.
• The integration tests refactored and optimized.