git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@197 7dcaeef0-15fb-0310-b436-a5af3365683c
split of the sftp_async_read function git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@188 7dcaeef0-15fb-0310-b436-a5af3365683c