Force creation of empty candles on new day. refs #106

If we reach a new day without having a previous fetch trigger the
creation of a new day there is a possibility we reach a weird edge
case where the expected most recent candle has a higher candle start
point than the first candle in the batch. To prevent an infinite loop
we force empty candles to be created for the new day.
Added openDay(), loadDay() and addCandles methods to CSV candleStore.
Tidy up of candleStore test.
Commentary fixup.
fixed #131
styling of csv store
styling of csv store (please 2 spaces as tab guys)
small improvements candlestore
re added my tests
renamed history handler
fixed #115