Update with exception handling

As long as the sketch is started with internet, 
this version can survive if internet goes down
then it carries on with last known data and stops updating its text file
IF INTERNET IS RESTORED, it continues and restarts appending data
What is not yet happening is the use of newly harvested data.
it appears to be using the load set...
Moved initial stopword check out of draw()

having a url call in draw() is a huge performance risk. Stop words only need to be removed on launch (or possible on grabtweet()!
Merge pull request #44 from rosemarybeetle/dev

Update Master with latest stable dev version