libssh2 1.2.5

This release includes the following changes:

 o Added Add keep-alive support: libssh2_keepalive_config() and
   libssh2_keepalive_send()
 o Added libssh2_knownhost_addc(), libssh2_init() and libssh2_exit()
 o Added LIBSSH2_SFTP_S_IS***() macros

This release includes the following bugfixes:

 o fix memory leak in libssh2_session_startup()
 o added missing error codes - shown as hangs in blocking mode
 o fix memory leak in userauth_keyboard_interactive()
 o libssh2_knownhost_del: fix write to freed memory
 o Send and receive channel EOF before sending SSH_MSG_CHANNEL_CLOSE
 o Use AES-CTR from OpenSSL when available
 o Fixed gettimeofday to compile with Visual C++ 6
 o NULL dereference when window adjusting a non-existing channel
 o avoid using poll on interix and mac os x systems
 o fix scp memory leak
 o Correctly clear blocking flag after sending multipart packet
 o Reduce used window sizes by factor 10
 o libssh2_userauth_publickey_fromfile_ex() handles a NULL password
 o sftp_init() deal with _libssh2_channel_write() short returns

This release would not have looked like this without help, code, reports and
advice from friends like these:

 Peter Stuge, Simon Josefsson, Alexander Lamaison, Paul Querna, Suyog Jadhav,
 Lars Nordin
 
        Thanks! (and sorry if I forgot to mention someone)
