Show hostname instead of IP in errors

Signed-off-by: John Spray <john.spray@inktank.com>
Capture stderr and include in CommandFailedError

Signed-off-by: John Spray <john.spray@inktank.com>
Remove spurious print

This was causing junk output like <type 'exceptions.StopIteration'>

Signed-off-by: John Spray <john.spray@inktank.com>
Timestamp stdout log output

Signed-off-by: John Spray <john.spray@inktank.com>
Catch a case where we weren't getting tracebacks

Signed-off-by: John Spray <john.spray@inktank.com>
Log correct name of context during errors

(instead of GeneratorContextManager)

Signed-off-by: John Spray <john.spray@inktank.com>
Spelling

Signed-off-by: John Spray <john.spray@inktank.com>