allow use of historical data

[mattvenn]

so you can see what your generator's patterns would look like on a given data set.

[mattvenn]

got a command line admin fix. use ./history/getHistory.py to fetch data, then use ./testsite/resouces/post_data.py --file history.json to post the data to the required datastream

[mattvenn]

nearly works on the generator page. From and to date should be a calendar widget.