Add other market data sources

[Lenskiy]

https://www.quandl.com/api/v3/datasets/WIKI/AAPL.csv?start_date=2010-01-01&api_key=...

https://stooq.com/q/d/l/?s=AAPL.US&i=d

https://www.alphavantage.co/query?function=TIME_SERIES_DAILY_ADJUSTED&symbol=AAPL&outputsize=full&apikey=...&datatype=csv

https://api.iextrading.com/1.0/stock/aapl/chart/5y?format=csv

https://marketdata.websol.barchart.com/getHistory.csv?apikey=...&symbol=AAPL&startDate=20100101&splits=true&dividends=true&volume=sum&nearby=1&jerq=true

http://www.google.com/finance/getprices?q=GOOGL&i=604800&p=10Y&f=d,c,v,k,o,h,l

[Lenskiy]

http://www.financial-hacker.com/bye-yahoo-and-thank-you-for-the-fish/

[Lenskiy]

https://www.stock-data-solutions.com/kb/how-to-load-historical-prices-from-google-finance-to-csv.htm