Log Message:
Update to 0.12.
- Bumped libssh2 version requirement to 1.2 (aug 2009)
- Added ssh2_auth_agent() - SSH agent authentication support
  (with libssh >= 1.2.3)
- Added ssh2_sftp_chmod() (fixed bug #59880)
- Added support for stream_set_timeout() to channel streams (fixed bug
  #56377) (with libssh >= 1.2.9)
- Added keyboard-interactive to ssh2_auth_password() (fixed bugs #61760
  and #54916)
- Add license file as requested in bug #59980
- Allow for tilde (~) in public and private keyfile paths
- Be more verbose about any errors within ssh2_scp_send
- Fixed bug #56425 - Problem with ssh2_scp_send
- Fixed bug #59794 - ssh2.sftp protocol wrapper works incorrectly for
  paths which contain a '#'
- Fixed bug #63192 - Check if connection is authenticated.
- Fixed bug #58576 - Handle error values from reads and writes to a channel.