#73 Display Timeout value for TIMEOUT_HIT msgs

[Clifton Wood]

For Slash::Utility::System::prog2file().

When the system returns a TIMEOUT_HIT error message, would it be
possible to also return the timeout value that was returned? So,
instead of "TIMEOUT_HIT", it would be "TIMEOUT_HIT ($timeout)".

Just a minor optimization in the error message.