Error message should be better if connection lost during testing also other keywords than Enable SSH Logging about sshlibrary

[spooning]

Originally submitted to Google Code by @yanne on 23 Feb 2009

Actually, I think that the above error message only comes in these two cases:

1. Library has been imported and no connection has been opened yet.
2. Close all connections -keyword has been used and no new connection has been opened.

Regardless of that, there is currently no code to detect whether the underlying ssh
connection is still alive when Execute Command is used. This could easily be changed
(although testing it properly might be a bit challenging)

[spooning]

Originally submitted to Google Code by @yanne on 27 Feb 2009

Fixed in r66