Changed file input so it can feed from named pipes.

The 'follow' flag allows it to maintain connection even if the producer
disappears - for example, if the kafka consumer which is feeding the
pipe disappears. Essentially, this allows for 'tail -f' style
functionality.
Updated kafka ingest.

This now really is just for the 'quick and dirty' - if you want to do
this 'for real', you should use a kafka consumer to feed a named pipe,
and 'esload' to read from the pipe with 'follow' flag set.