Include more data

[jgmill]

• [x] French renewable generation from RTE. Data only starts in 2015 unfortunately

• [ ] Spanish renewable generation from REE

• [x] Austrian wind and solar generation from APG starts 2010

• [ ] Austrian wind generation fomr Ömag starts 2003

• [ ] Finnish wind generation from Fingrid

• [x] Italian renewables generation from Terna

• [x] UK renewables generation from Elexon

• [ ] German and Nordic day-ahead spot price data in DKK from Energinet.dk

• [x] Load Data for Nordic countries before 2010

• [x] Load data from new ENTSO E Power Statistics