SSH package for U++
--------------------
SSH package is a flexible, easy-to-use, yet powerful libssh2 wrapper for Ultimate++.
It supports both console and GUI-based applications on POSIX-compliant operating systems and
MS Windows (tm).

Classes:
--------------------

- Base (core) class  -> Ssh
  - Ssh session        -----> SshSession
  - Sftp subsystem     -----> SFtp
     -  SFtp Stream interface       -----> SFtpStream
     -  File system transparency    -----> SFtpFileSystemInfo 
  - Ssh channel        -----> SshChannel
      - Scp channel                 -----> Scp
      - Exec channel                -----> SshExec
      - Real-time interactive shell -----> SshShell
      - X11 forwarding              -----> SshShell (as operation mode)      
      - Tcp/IP and port forwarding  -----> SshTunnel
- Known hosts manager -> SshHosts

Features and Highlights:
--------------------

- Ssh-derived classes have pick semantics, based on RAII principle, support RTTI, and allow
  polymorphism (i.e. different classes can be stored in the same array, etc.) through a common
  interface. 
- Uses U++'s memory manager (Native manager (malloc) is also a compile-time option)
- Uses OpenSSL by default. 
- Supports multithreading.
- Supports 3rd-party network proxies.
- Supports known hosts verification mechanism.
- Supports password, public key, host-based, and keyboard-interactive authentication methods.
- Supports ssh-agents.
- Supports real-time interactive command line (shell) interface with both console and GUI integration
  (SshShell works on both Windows and Posix-compliant OSes)
- Supports X11 forwarding. 
  (A single SShShell instance is capable of handling multiple X11 requests simultaneously.)
- Supports Tcp/IP and port forwarding.
- Supports stream operations on SFTP objects.
- Supports access to sftp folder hiearcy in a file-system-agnostic (transparent) way.
- Supports detailed (full) debug logging.

Reference examples:
-------------------

- SshBasics:    Demonstrates basic capabilities of SSH package.
- SFtpFileSel:  Demonstrates FileSel integration of SFtp class, using FileSystemInfo interface.
- SFtpBrowser:  Demonstrates a basic sftp browser with GUI.