Making the Raspi example more reliable

[ctmalan]

It seems that poor network conditions causes the Raspi example to fail.

This can be improved by moving the lines: feed = api.feeds.get(FEED_ID) and datastream = get_datastream(feed) into the while True: loop.

Any better suggestions will be most welcome.

Refer to http://stackoverflow.com/questions/19808512/data-to-and-fro-hang-xively/21086914#21086914

[stetelepta]

Thanks, ran into that too.