gridSpy: read-only data file naming conventions

Suggest the following under hum-csafe/Research Projects/GREEN Grid/_RAW DATA/GridSpyData:

/1min = 1 min data /1sec = 1 second data

within 1/min -> rf_x/ where x = dwelling id

within a given rf_x/ daily files are stored as year-month-day-at1.csv <- this makes it much easier to parse the date from the file name. This in turn makes it easier to filter the filelist to only load the ones you actually want.