Release 1.7.0

Changes

• Better tunneling implementation for native clients that supports multiple tunnels over single SSH connection for connecting multiple hosts through single proxy.
• Added greenlet_timeout setting to native client run_command to pass on to getting greenlet result to allow for greenlets to timeout.
• Native client raises specific exceptions on non-authentication errors connecting to host instead of generic SessionError.

Fixes

• Native client tunneling would not work correctly - #123.
• timeout setting was not applied to native client sockets.
• Native client would have SessionError instead of Timeout exceptions on timeout errors connecting to hosts.