libssh2 1.4.3

This release includes the following changes:

 o compression: add support for zlib@openssh.com

This release includes the following bugfixes:

 o sftp_read: return error if a too large package arrives
 o libssh2_hostkey_hash.3: update the description of return value
 o Fixed MSVC NMakefile
 o examples: use stderr for messages, stdout for data
 o openssl: do not leak memory when handling errors
 o improved handling of disabled MD5 algorithm in OpenSSL
 o known_hosts: Fail when parsing unknown keys in known_hosts file
 o configure: gcrypt doesn't come with pkg-config support
 o session_free: wrong variable used for keeping state
 o libssh2_userauth_publickey_fromfile_ex.3: mention publickey == NULL
 o comp_method_zlib_decomp: handle Z_BUF_ERROR when inflating

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

 Guenter Knauf, Peter Stuge, TJ Saunders, Mike Abdullah, Maxime Larocque,
 Dmitry Smirnov, Dave Hayden, Peter Krempa, Kamil Dudka
 
        Thanks! (and sorry if I forgot to mention someone)

